WorldWideScience

Sample records for biomass fired grate

  1. Grate Firing of Biomass: Measurements, Validation and Demonstration

    DEFF Research Database (Denmark)

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

    , the development of combustion technology has followed two specific paths: grate firing and co-firing in conventional fossil fuel fired plants. Over the past decade, the research and development work related to biomass grate firing and co-firing has been extensive and the two technologies have now been developed...... to give viable technical solutions. Particularly, the fundamental knowledge achieved in grate firing makes it a presently preferred technology in Denmark. Grate firing plants have undergone significant development, leading to increased electrical efficiency and greater reliability. However...... to the complexity of the solid biomass fuel bed on the grate, the turbulent reacting flow in the combustion chamber and the intensive interaction between them. Therefore, development and test of biomass fuel bed models is one of the major concerns in this report, as well as the methodology of modelling grate...

  2. Grate-firing of biomass for heat and power production

    DEFF Research Database (Denmark)

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

    2008-01-01

    As a renewable and environmentally friendly energy source, biomass (i.e., any organic non-fossil fuel) and its utilization are gaining an increasingly important role worldwide Grate-firing is one of the main competing technologies in biomass combustion for heat and power production, because it can...... bed on the grate, and the advanced secondary air supply (a real breakthrough in this technology) are highlighted for grate-firing systems. Amongst all the issues or problems associated with grate-fired boilers burning biomass, primary pollutant formation and control, deposition formation and corrosion...

  3. Numerical simulation of a biomass fired grate boiler

    DEFF Research Database (Denmark)

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

    2006-01-01

    Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion furnace of a biomass-fired grate boiler provides crucial insight into the boiler's performance. Quite a few factors play important roles in a general CFD analysis, such as grid, models, discretization scheme and so on...

  4. Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Aho, Martti;

    2013-01-01

    -scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory...... in order to simulate the sulfation of KCl by ferric sulfate addition during grate-firing of biomass. The simulation results show good agreements with the experimental data obtained in a pilot-scale biomass grate-firing reactor, where different amounts of ferric sulfate was injected on the grate...

  5. Mathematical modeling and experimental study of biomass combustion in a thermal 108 MW grate-fired boiler

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren K.;

    2008-01-01

    Grate boilers are widely used to fire biomass for heat and power production. However grate-firing systems are often reported to have relatively high un-burnout, low efficiency and high emissions, and need to be optimized and modernized. This paper presents the efforts towards a reliable baseline...

  6. Ash transformation and deposit build-up during biomass suspension and grate firing: Full-scale experimental studies

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    2012-01-01

    of this study was to investigate ash transformation and deposition behavior in two biomass-fired boilers, firing wheat straw and/or wood. The influence of strawfiring technology (grate and suspension) on the ash transformation, deposit formation rate and deposit characteristics has been investigated. Bulk...... elemental analysis of fly ashes revealed that fly ash from suspension firing of straw has high contents of Si, K and Ca, while fly ash from straw firing on grate was rich in the volatile elements K, Cl and S. Investigations of deposit formation ratesweremade in the superheater and convective pass regions...... of the boilers by use of an advanced online deposit probe. During straw firing on grate, the measured deposit formation ratewas close to 38 g/m2/h. Data fromstraw suspension firing showed a deposit formation rate of 41 g/m2/h. The deposit formation rates during straw suspension firing and straw grate firing were...

  7. Deposit Probe Measurements in Large Biomass-Fired Grate Boilers and Pulverized-Fuel Boilers

    DEFF Research Database (Denmark)

    Hansen, Stine Broholm; Jensen, Peter Arendt; Jappe Frandsen, Flemming;

    2014-01-01

    temperatures (>900 °C). At lower flue gas temperatures, the deposits can be removed by soot blowing. The required soot blower impact pressure is strongly influenced by the surface temperature, such that a high surface temperature makes the deposit more difficult to remove. During straw/wood......-up increased with the K-content of the fuel ash and fly ash for grate-fired boilers. For suspension-fired boilers, deposition rates are comparatively low for wood-firing and increase with increasing fuel straw shares. Shedding of deposits occurs by melting during straw-firing on a grate at high flue gas......-firing in suspension-fired boilers, shedding occurred by debonding with incomplete removal at flue gas temperatures of 600–1000 °C and by debonding with complete removal during wood-firing in suspension-fired boilers at high flue gas temperatures (1300 °C). Shedding events were not observed during wood suspension...

  8. Hygroscopic behaviour of aerosol particles emitted from biomass fired grate boilers

    Energy Technology Data Exchange (ETDEWEB)

    Rissler, Jenny; Swietlicki, Erik [Lund Univ. (Sweden). Div. of Nuclear Physics; Pagels, Joakim; Wierzbicka, Aneta; Bohgard, Mats [Lund Univ. (Sweden). Div. of Ergonomics and Aerosol Technology; Strand, Michael; Lillieblad, Lena; Sanati, Mehri [Vaexjoe Univ. (Sweden). Bioenergy Technology

    2005-02-01

    This study focuses on the hygroscopic properties of sub-micrometer aerosol particles emitted from two small-scale district heating combustion plants (1 and 1.5 MW) burning two types of biomass fuels (moist forest residue and pellets). The hygroscopic particle diameter growth was measured when taken from a dehydrated to a humidified state for particle diameters between 30-350 nm (dry size) using a Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA). Particles of a certain dry size all showed similar hygroscopic growth and the average diameter growth at RH=90% for 110/100 nm particles was 1.68 in the 1 MW boiler, and 1.52 in the 1.5 MW boiler. These growth factors are considerably higher in comparison to other combustion aerosol particles such as diesel exhaust, and are the result of the efficient combustion and the high concentration of alkali species in the fuel. The observed water uptake could be explained using the Zdanovskii-Stokes-Robinson (ZSR) mixing rule and a chemical composition of only potassium salts, taken from an Ion Chromatography analysis of filter sample (KCl, K{sub 2}SO{sub 4}, and K{sub 2}CO{sub 3}). Agglomerated particles collapsed and became more spherical when initially exposed to a moderately high relative humidity. When diluting with hot particle-free air, the fractal-like structures remained intact until humidified in the HTDMA. A method is presented to by which to estimate the fractal dimension of the agglomerated combustion aerosol and correct the measured mobility diameter hygroscopic growth to the more useful property volume growth. The fractal dimension was estimated to be {approx}2.5.

  9. Biomass co-firing

    DEFF Research Database (Denmark)

    Yin, Chungen

    2013-01-01

    Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized...

  10. Characterizing and modeling of an 88 MW grate-fired boiler burning wheat straw: Experience and lessons

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse Aistrup; Clausen, Sønnik;

    2012-01-01

    Grate-firing is one of the main technologies currently used for biomass combustion for heat and power production. However, grate-firing is yet to be further developed, towards a better technology for biomass combustion, particularly towards higher efficiency, lower emissions, and better reliability...... and availability. To better understand grate-firing of biomass and to establish a reliable but relatively simple Computational Fluid Dynamics (CFD) modeling methodology for industrial applications, biomass combustion in a number of different grate boilers has been measured and modeled. As one of the case studies...

  11. The behavior of ash species in suspension fired biomass boilers

    OpenAIRE

    Jensen, Peter Arendt

    2015-01-01

    While fluid bed and grate fired boilers initially was the choice of boilers used for power production from both wood and herbaceous biomass, in recent years suspension fired boilers have been increasingly used for biomass based power production. In Denmark several large pulverized fuel boilers have been converted from coal to biomass combustion in the last 15 years. This have included co-firing of coal and straw, up to 100% firing of wood or straw andthe use of coal ash as an additive to reme...

  12. Development of generalised model for grate combustion of biomass

    DEFF Research Database (Denmark)

    Rosendahl, Lasse; Kær, Søren Knudsen; Sørensen, Henrik

    is big enough to represent real, full scale conditions, and yet small enough to be operational in terms of parameter studies of different nature. Apart from full SRO data, measurements (gas sampling, velocity, temperature, particle sampling) can be taken through a heated, water-cooled probe......This project has been divided into two main parts, one of which has focused on modelling and one on designing and constructing a grate fired biomass test rig. The modelling effort has been defined due to a need for improved knowledge of the transport and conversion processes within the bed layer...... in a spatially resolved grid, much in the same manner as in a finite volume CFD code. Within this porous layer of fuel, gas flows according to the Ergun equation. The diffusion coefficient links the properties of the fuel to the grate type and vibration mode, and is determined for each combination of fuel, grate...

  13. Modeling and experiments of biomass combustion in a large-scale grate boiler

    DEFF Research Database (Denmark)

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

    2007-01-01

    is exposed to preheated inlet air while the top of the bed resides within the furnace. Mathematical modeling is an efficient way to understand and improve the operation and design of combustion systems. Compared to modeling of pulverized fuel furnaces, CFD modeling of biomass-fired grate furnaces...... is inherently more difficult due to the complexity of the solid biomass fuel bed on the grate, the turbulent reacting flow in the combustion chamber and the intensive interaction between them. This paper presents the CFD validation efforts for a modern large-scale biomass-fired grate boiler. Modeling...... quite much with the conditions in the real furnace. Combustion instabilities in the fuel bed impose big challenges to give reliable grate inlet BCs for the CFD modeling; the deposits formed on furnace walls and air nozzles make it difficult to define precisely the wall BCs and air jet BCs...

  14. 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...

  15. Deposit Probe Measurements in Danish Grate and Pulverized Fuel Biomass Power Boilers

    DEFF Research Database (Denmark)

    Hansen, Stine Broholm; Jensen, Peter Arendt; Jappe Frandsen, Flemming;

    2012-01-01

    formation rates. Suspension fired boilers generate more fly ash, while grate boilers form a fly ash with a higher fraction of melt formation (and thereby a higher sticking probability) at similar temperatures. For suspension fired units it is observed that wood with a lower ash content than straw gives rise....... Corresponding samples of fuels, ash deposits and fly ash have provided information on the transformation of inorganics in the boiler. Generally, grate fired boilers provide a fly ash containing high contents of K, Cl and S compared to the fuel ash, while suspension fired boilers fly ash has a composition nearly...... similar to the fuel ash. Inner most biomass deposits are always salt-rich, while thicker deposit layers also contain some Si and Ca. Deposit probe formation rate measurements have been performed in different ways on several boilers. Grate and suspension fired boilers seems to cause similar deposit...

  16. Design of 500kW grate fired test facility using CFD

    DEFF Research Database (Denmark)

    Rosendahl, Lasse Aistrup; Kær, Søren Knudsen; Jørgensen, K.

    2005-01-01

    A 500kW vibrating grate fired test facility for solid biomass fuels has been designed using numerical models including CFD. The CFD modelling has focussed on the nozzle layout and flowpatterns in the lower part of the furnace, and the results have established confidence in the chosen design...

  17. Numerical modelling of a straw-fired grate boiler

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2004-01-01

    The paper presents a computational fluid dynamics (CFD) analysis of a 33 MW straw-fired grate boiler. Combustion on the grate plays akey-role in the analysis of these boilers and in this work a stand-alone code was used to provide inlet conditions for the CFD analysis. Modelpredictions were compa...... mixing in the furnace is a key issue leading to these problems. q 2003 Elsevier Ltd. All rights reserved....

  18. Bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.;

    2013-01-01

    Because of the complexity to describe and solve thermo-chemical processes occurring in a fuel bed in grate-fired boiler, it is often necessary to simplify the process and use modeling techniques based on overall mass, energy and species conservation. A comparison between two numerical models...... to describe the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. In this work both models consider the incoming solid fuel as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is treated as a 0D system, but the thermo...... concentrations and velocity of the producer gas leaving the fuel bed provided by the two models are compared. A sensitivity analysis with respect to mass flow rate of the primary air is also performed, as well as a further comparison regarding the dependence of the producer gas properties on the initial moisture...

  19. Suspension-Firing of Biomass

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    2012-01-01

    This paper is the second of two papers, describing probe measurements of deposit buildup and removal (shedding), conducted in a 350 MWth suspension-fired boiler, firing straw and wood. Investigations of deposit buildup and shedding have been made by use of an advanced online deposit probe and a...... sootblowing probe. The influences of feedstock (i.e., straw share in wood), flue gas temperature (600−1050 °C), probe surface temperature (500 and 600 °C), and probe exposure time on deposit shedding have been quantified. Quantification of naturally occurring deposit shedding and deposit shedding during plant...

  20. Suspension-Firing of Biomass

    DEFF Research Database (Denmark)

    Bashir, Muhammad Shafique; Jensen, Peter Arendt; Frandsen, Flemming;

    2012-01-01

    , followed the same trends. Ash transformation was investigated by bulk ash analysis of the fuel, fly, and bottom ash during straw and/or wood suspension firing. Bulk ash analysis of fly ashes showed that the contents of volatile elements (K, Cl, S) were slightly greater than in the fuel ash, while Ca and Si...... remained either in the same proportion or were slightly reduced. It was also found that, with an increase in fuel ash K/Si molar ratio, the concentration of the volatile elements, K, Cl, and, to some extent, S, increased in the fly ash. The bottom ash was dominated by Si and Ca, with almost no S and Cl...... gas temperature (600–1050 °C) on ash deposit formation rate has been investigated. Investigations of deposit formation rate were made by use of an advanced online deposit probe that allowed nearly continuous measurement of the deposited mass. Two different measures of deposit formation rate are used...

  1. GASIFICATION BASED BIOMASS CO-FIRING

    Energy Technology Data Exchange (ETDEWEB)

    Babul Patel; Kevin McQuigg; Robert Toerne; John Bick

    2003-01-01

    Biomass gasification offers a practical way to use this widespread fuel source for co-firing traditional large utility boilers. The gasification process converts biomass into a low Btu producer gas that can be used as a supplemental fuel in an existing utility boiler. This strategy of co-firing is compatible with a variety of conventional boilers including natural gas and oil fired boilers, pulverized coal fired conventional and cyclone boilers. Gasification has the potential to address all problems associated with the other types of co-firing with minimum modifications to the existing boiler systems. Gasification can also utilize biomass sources that have been previously unsuitable due to size or processing requirements, facilitating a wider selection of biomass as fuel and providing opportunity in reduction of carbon dioxide emissions to the atmosphere through the commercialization of this technology. This study evaluated two plants: Wester Kentucky Energy Corporation's (WKE's) Reid Plant and TXU Energy's Monticello Plant for technical and economical feasibility. These plants were selected for their proximity to large supply of poultry litter in the area. The Reid plant is located in Henderson County in southwest Kentucky, with a large poultry processing facility nearby. Within a fifty-mile radius of the Reid plant, there are large-scale poultry farms that generate over 75,000 tons/year of poultry litter. The local poultry farmers are actively seeking environmentally more benign alternatives to the current use of the litter as landfill or as a farm spread as fertilizer. The Monticello plant is located in Titus County, TX near the town of Pittsburgh, TX, where again a large poultry processor and poultry farmers in the area generate over 110,000 tons/year of poultry litter. Disposal of this litter in the area is also a concern. This project offers a model opportunity to demonstrate the feasibility of biomass co-firing and at the same time eliminate

  2. Biomass Burning Emissions from Fire Remote Sensing

    Science.gov (United States)

    Ichoku, Charles

    2010-01-01

    Knowledge of the emission source strengths of different (particulate and gaseous) atmospheric constituents is one of the principal ingredients upon which the modeling and forecasting of their distribution and impacts depend. Biomass burning emissions are complex and difficult to quantify. However, satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP), which has a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. In this presentation, we will show how the satellite measurement of FRP is facilitating the quantitative characterization of biomass burning and smoke emission rates, and the implications of this unique capability for improving our understanding of smoke impacts on air quality, weather, and climate. We will also discuss some of the challenges and uncertainties associated with satellite measurement of FRP and how they are being addressed.

  3. Selective Logging, Fire, and Biomass in Amazonia

    Science.gov (United States)

    Houghton, R. A.

    1999-01-01

    Biomass and rates of disturbance are major factors in determining the net flux of carbon between terrestrial ecosystems and the atmosphere, and neither of them is well known for most of the earth's surface. Satellite data over large areas are beginning to be used systematically to measure rates of two of the most important types of disturbance, deforestation and reforestation, but these are not the only types of disturbance that affect carbon storage. Other examples include selective logging and fire. In northern mid-latitude forests, logging and subsequent regrowth of forests have, in recent decades, contributed more to the net flux of carbon between terrestrial ecosystems and the atmosphere than any other type of land use. In the tropics logging is also becoming increasingly important. According to the FAO/UNEP assessment of tropical forests, about 25% of total area of productive forests have been logged one or more times in the 60-80 years before 1980. The fraction must be considerably greater at present. Thus, deforestation by itself accounts for only a portion of the emissions carbon from land. Furthermore, as rates of deforestation become more accurately measured with satellites, uncertainty in biomass will become the major factor accounting for the remaining uncertainty in estimates of carbon flux. An approach is needed for determining the biomass of terrestrial ecosystems. 3 Selective logging is increasingly important in Amazonia, yet it has not been included in region-wide, satellite-based assessments of land-cover change, in part because it is not as striking as deforestation. Nevertheless, logging affects terrestrial carbon storage both directly and indirectly. Besides the losses of carbon directly associated with selective logging, logging also increases the likelihood of fire.

  4. Development of generalised model for grate combustion of biomass. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl, L.

    2007-02-15

    This project has been divided into two main parts, one of which has focused on modelling and one on designing and constructing a grate fired biomass test rig. The modelling effort has been defined due to a need for improved knowledge of the transport and conversion processes within the bed layer for two reasons: 1) to improve emission understanding and reduction measures and 2) to improve boundary conditions for CFD-based furnace modelling. The selected approach has been based on a diffusion coefficient formulation, where conservation equations for the concentration of fuel are solved in a spatially resolved grid, much in the same manner as in a finite volume CFD code. Within this porous layer of fuel, gas flows according to the Ergun equation. The diffusion coefficient links the properties of the fuel to the grate type and vibration mode, and is determined for each combination of fuel, grate and vibration mode. In this work, 3 grates have been tested as well as 4) types of fuel, drinking straw, wood beads, straw pellets and wood pellets. Although much useful information and knowledge has been obtained on transport processes in fuel layers, the model has proved to be less than perfect, and the recommendation is not to continue along this path. New visual data on the motion of straw on vibrating grates indicate that a diffusion governed motion does not very well represent the transport. Furthermore, it is very difficult to obtain the diffusion coefficient in other places than the surface layer of the grate, and it is not likely that this is representative for the motion within the layer. Finally, as the model complexity grows, model turnover time increases to a level where it is comparable to that of the full furnace model. In order to proceed and address the goals of the first paragraph, it is recommended to return to either a walking column approach or even some other, relatively simple method of prediction, and combine this with a form of randomness, to mimic the

  5. Biomass Co-Firing in Suspension-Fired Power Plants

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen; Hvid, Søren Lovmand; Baxter, Larry

    , in the future it is expected to become relevant to cofire in more advanced plants as the trend in the power plant structure is towards older plants having fewer operating hours or being decommissioned. A major product of this project is an experimentally validated computational fluid dynamics (CFD) based......The objective of the project is to investigate critical issues associated with cofiring with low-NOx burners and cofiring in advanced suspension-fired plants with for example high-temperature steam cycles. Experience has been gained using biofuels for cofiring in older power plant units. However...... of advanced cofired combustion and potentially gasification systems and secondarily to resolve immediate and critical issues associated with cofired systems. Another essential issue is the assessment of fuel flexibility in cofired plants to help keep biomass use competitive compared to other renewable...

  6. Materials Problems and Solutions in Biomass Fired Plants

    DEFF Research Database (Denmark)

    Larsen, Ole Hede; Montgomery, Melanie

    2006-01-01

    Due to Denmark’s pledge to reduce carbon dioxide emissions, biomass is utilised increasingly as a fuel for generating energy. Extensive research and demonstration projects especially in the area of material performance for biomass fired boilers have been undertaken to make biomass a viable fuel...

  7. Technical and Economic Aspects of Biomass Co-Firing in Coal-Fired Boilers

    Directory of Open Access Journals (Sweden)

    Dzikuć M.

    2014-11-01

    Full Text Available The article presents the analysis of the potential of using biomass and coal co-firing in the Polish electro energetic system and shows the benefits resulting from an increase of biomass amount in electricity production in one of the largest Polish power stations. The paper discusses the most often used technologies for biomass co-firing and the potential of using biomass in electricity production in Poland. It also emphasises the fact that biomass co-firing allows a reduction of greenhouse gases emissions to the atmosphere and helps decrease consumption of energy resources. The article also emphasises the economic meaning of increasing the share of renewable energy resources in energy balance, including biomass, due to costs related to greenhouse gases emissions charges. Finally, conclusions from using biomass and coal co-firing in electricity production are presented

  8. GASIFICATION BASED BIOMASS CO-FIRING - PHASE I

    Energy Technology Data Exchange (ETDEWEB)

    Babul Patel; Kevin McQuigg; Robert F. Toerne

    2001-12-01

    Biomass gasification offers a practical way to use this locally available fuel source for co-firing traditional large utility boilers. The gasification process converts biomass into a low Btu producer gas that can be fed directly into the boiler. This strategy of co-firing is compatible with variety of conventional boilers including natural gas fired boilers as well as pulverized coal fired and cyclone boilers. Gasification has the potential to address all problems associated with the other types of co-firing with minimum modifications to the existing boiler systems. Gasification can also utilize biomass sources that have been previously unsuitable due to size or processing requirements, facilitating a reduction in the primary fossil fuel consumption in the boiler and thereby reducing the greenhouse gas emissions to the atmosphere.

  9. Benefits of Allothermal Biomass Gasification for Co-Firing

    Energy Technology Data Exchange (ETDEWEB)

    Van der Meijden, C.M.; Van der Drift, A.; Vreugdenhil, B.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2012-04-15

    Many countries have set obligations to reduce the CO2 emissions from coal fired boilers. Co-firing of biomass in existing coal fired power plants is an attractive solution to reduce CO2 emissions. Co-firing can be done by direct mixing of biomass with coal (direct co-firing) or by converting the biomass into a gas or liquid which is fired in a separate burner (indirect co-firing). Direct co-firing is a rather simple solution, but requires a high quality and expensive biomass fuel (e.g. wood pellets). Indirect co-firing requires an additional installation that converts the solid biomass into a gas or liquid, but has the advantage that it can handle a wide range of cheap biomass fuels (e.g. demolition wood) and most of the biomass ash components are separated from the gas before it enters the boiler. Separation of biomass ash can prevent fouling issues in the boiler. Indirect co-firing, using biomass gasification technology, is already common practice. In Geertruidenberg (the Netherlands) a 80 MWth Lurgi CFB gasifier produces gas from demolition wood which is co-fired in the Amer PC boiler. In Ruien (Belgium) a 50 MWth Foster Wheeler fluidized bed gasifier is in operation. The Energy research Centre of the Netherlands (ECN) developed a 'second generation' allothermal gasifier called the MILENA gasifier. This gasifier has some major advantages over conventional fluidized bed gasifiers. The heating value of the produced gas is approximately 2.5 times higher than of gas produced by conventional bubbling / circulating fluidized bed gasifiers. This results in smaller adaptations to the membrane wall of the boiler for the gas injection, thus lower costs. A major disadvantage of most fluidized bed gasifiers is the incomplete conversion of the fuel. Typical fuel conversions vary between 90 and 95%. The remaining combustible material, also containing most of the biomass ash components, is blown out of the gasifier and removed from the gas stream by a cyclone to

  10. Biomass fires: preliminary estimation of ecosystems global economic losses

    OpenAIRE

    Chatenoux, Bruno; Peduzzi, Pascal

    2013-01-01

    Globally, biomass fires are burning yearly (in average) between 3 and 4.5 million km2 depending on years and sensor used. Africa is by far the main region affected. Biomass fires affect both local and global environment. With impacts to local biodiversity, soil, as well as produce large amount of Green House Gases affecting the global climate. Methodologies for evaluating the value of ecosystems (and related services) are still in their preliminary stage and there are large level of uncertain...

  11. Cajander larch (Larix cajanderi biomass distribution, fire regime and post-fire recovery in northeastern Siberia

    Directory of Open Access Journals (Sweden)

    M. C. Mack

    2012-10-01

    Full Text Available Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes and post-disturbance ecosystem recovery. Our primary objective here was to analyse post-fire accumulation of Cajander larch (Larix cajanderi Mayr. aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated c. 1966–2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≤ 25 yr, 271 ± 26 g m−2, n = 66 [mean ± SE] and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33–38 yr, 746 ± 100 g m−2, n = 32, though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr−1 × 104 km−2 than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr−1 × 104 km−2. The MODIS burned area maps underestimated the total area burned in this region from 2000–2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery

  12. Cajander larch (Larix cajanderi biomass distribution, fire regime and post-fire recovery in northeastern Siberia

    Directory of Open Access Journals (Sweden)

    S. J. Goetz

    2012-06-01

    Full Text Available Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes, and post-disturbance ecosystem recovery. Our primary objective here was to analyze post-fire accumulation of Cajander larch (Larix cajanderi Mayr. aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated ca. 1969–2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≥ 25 yr, 271 ± 26 g m−2, n=66 [mean ± SE] and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33–38 yr, 746 ± 100 g m−2, n=32, though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr−1 × 104 km−2 than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr−1 × 104 km−2. The MODIS burned area maps underestimated the total area burned in this region from 2000–2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery

  13. Cajander larch (Larix cajanderi) biomass distribution, fire regime and post-fire recovery in northeastern Siberia

    Science.gov (United States)

    Berner, L. T.; Beck, P. S. A.; Loranty, M. M.; Alexander, H. D.; Mack, M. C.; Goetz, S. J.

    2012-10-01

    Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes and post-disturbance ecosystem recovery. Our primary objective here was to analyse post-fire accumulation of Cajander larch (Larix cajanderi Mayr.) aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated c. 1966-2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≤ 25 yr, 271 ± 26 g m-2, n = 66 [mean ± SE]) and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33-38 yr, 746 ± 100 g m-2, n = 32), though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr-1 × 104 km-2) than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr-1 × 104 km-2). The MODIS burned area maps underestimated the total area burned in this region from 2000-2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery were strongly associated (r2 ≈ 0

  14. APPLICATION OF NUMERICAL MODELLING TO BIOMASS GRATE FURNACES

    OpenAIRE

    Mehrabian, Ramin

    2015-01-01

    The direct combustion of the biomass is the most advanced and mature technology in the field of energetic biomass utilisation. The legislations on the amount of emitted pollutants and the plant efficiency of biomass combustion systems are continually being restricted. Therefore constant improvement of the plant efficiency and emission reduction is required Numerical modelling is gaining increasing importance for the development of biomass combustion technologies. In this paper an overview abo...

  15. Materials Problems and Solutions in Biomass fired plants

    DEFF Research Database (Denmark)

    Larsen, Ole Hede; Montgomery, Melanie

    2006-01-01

    Owing to Denmark's pledge to reduce carbon dioxide emissions, biomass is being increasingly utilised as a fuel for generating energy. Extensive research and development projects, especially in the area of material performance for biomass fired boilers, have been undertaken to make biomass a viable...... fuel resource. When straw is combusted, potassium chloride and potassium sulphate are present in ash products, which condense on superheater components. This gives rise to specific chlorine corrosion problems not previously encountered in coal fired power plants. The type of corrosion attack can...

  16. The behavior of ash species in suspension fired biomass boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt

    formation in suspension fired boilers. The presentation provides an overview of the knowledge obtained with respect to ash species behavior insuspension fired biomass boilers. A mechanistic understanding of the fly ash formation process in biomass fired PF boilers isobtained today. A high fraction of alkali...... salt species are released to the gas phase during the initial fuel combustion process. The salt species are present in gas phase in the boil chamberand upon cooling in the convective pass aerosols are formed. Recent studies indicates that a large fraction of the residual condensed phase ash fragments...... to generate ash particles typically in the size range of 50 to 200 μm on biomass suspension fired power plant boilers. A fragmentation rate of fuel particles of 3 have been used to describe both the residual ash formation process in laboratory entrained flow reactors and in full scale boilers.A range...

  17. Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers

    DEFF Research Database (Denmark)

    Rajh, Boštjan; Yin, Chungen; Samec, Niko;

    Computational Fluid Dynamics (CFD) is increasingly used in industry for detailed understanding of the combustion process and for appropriate design and optimization of Waste–to–Energy (WtE) plants. In this paper, CFD modelling of waste wood combustion in a 13 MW grate-fired boiler in a WtE plant is...... presented. To reduce the risk of slagging, optimize the temperature control and enhance turbulent mixing, part of the flue gas is recycled into the grate boiler. In the simulation, a 1D in–house bed model is developed to simulate the conversion of the waste wood in the fuel bed on the grate, which provides...

  18. Untypical bromine corrosion in boilers co-firing biomass

    Directory of Open Access Journals (Sweden)

    A. Hernas

    2012-09-01

    Full Text Available Purpose: The aim of this study was to determine the untypical corrosion resistance of rotary air preheaters in a biomass co-fired power plant.Design/methodology/approach: The selected results of some components of regenerative rotary air preheaters in a biomass co-fired power plant are presented. The macro and microstructure of corroded components of a LUVO preheater after 3 years of service are presented. The chemical composition of corrosion products was determined by X-ray microanalysis.Findings: Data concerning toxicity and identification of PBDEs (Polibrominated diphenyl ethers in the biomass is very limited. The presented research provides information and the proposed corrosion reaction mechanism in environments containing biomass with aggressive compounds like Cl, Si, H and Br.Research limitations/implications: An extended research on PBDEs in power plant fuels is necessary to give a full assessment of the corrosion mechanism in the presented environment; obligatory classification of the co-fired biomass.Originality/value: Firstly, an assessment of the danger for boiler materials co-firing biomass containing brominated organic flame and presentation of the reaction during the corrosion process and degradation of power boiler components in the presented environment. Secondly, the highlighting of the problem that there is a need to properly select and determine the chemical composition of the biomass used.

  19. Short review on the origin and countermeasure of biomass slagging in grate furnace

    OpenAIRE

    Yiming eZhu; Yanqing eNiu; Houzhang eTan; Xuebin eWang

    2014-01-01

    Given the increasing demand for energy consumption, biomass has been more and more important as a new type of clean renewable energy source. Biomass direct firing is the most mature and promising utilization method to date, while it allows a timely solution to slagging problems. Alkali metal elements in the biomass fuel and the ash fusion behavior, as the two major origins contributing to slagging during biomass combustion, are analyzed in this paper. The slag presents various layered structu...

  20. Short review on the origin and countermeasure of biomass slagging in grate furnace

    Directory of Open Access Journals (Sweden)

    Yiming eZhu

    2014-02-01

    Full Text Available Given the increasing demand for energy consumption, biomass has been more and more important as a new type of clean renewable energy source. Biomass direct firing is the most mature and promising utilization method to date, while it allows a timely solution to slagging problems. Alkali metal elements in the biomass fuel and the ash fusion behavior, as the two major origins contributing to slagging during biomass combustion, are analyzed in this paper. The slag presents various layered structures affected by the different compositions of ash particles. Besides, the high-temperature molten material which provides a supporting effect on the skeletal structure in biomass ash was proposed to evaluate the ash fusion characteristics. In addition, numerous solutions to biomass slagging, such as additives, fuel pretreatment and biomass co-firing, were also discussed.

  1. Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power

    NARCIS (Netherlands)

    Kaiser, J.W.; Heil, A.; Andreae, M.O.; Benedetti, A.; Chubarova, N.; Jones, L.; Morcrette, J.J.; Razinger, M.; Schultz, M.G.; Suttie, M.; Werf, van der G.R.

    2012-01-01

    The Global Fire Assimilation System (GFASv1.0) calculates biomass burning emissions by assimilating Fire Radiative Power (FRP) observations from the MODIS instruments onboard the Terra and Aqua satellites. It corrects for gaps in the observations, which are mostly due to cloud cover, and filters spu

  2. Co-firing plans in the spotlight over biomass imports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Spurred by the renewables obligation, coal-fired power stations with a capacity of over 20GW could be co-firing with biomass by early next year. But, with little of their fuel coming from dedicated energy crops, the generators are in danger of entering a minefield. UK wood panel manufacturers fear that their raw material costs will rise in the face of subsidised competition from power stations, while the generators' growing biomass imports are stirring sensitivities about rainforest destruction and dislocation of overseas markets for agricultural by-products. 1 tab., 2 photos.

  3. Biomass fuelled indirect fired micro turbine

    Energy Technology Data Exchange (ETDEWEB)

    Pritchard, D.

    2005-07-01

    This report summarises the findings of a project to further develop and improve a system based on the Bowman TG50 50kWe turbine and a C3(S) combustor with a high temperature heat exchanger for the production of electricity from biomass. Details are given of the specific aims of the project, the manufacture of a new larger biomass combustor, the development of startup and shutdown procedures, waste heat recuperation, adaption of a PC-based mathematical model, and capital equipment costs. The significant levels of carbon emission savings and the commercial prospects of the biomass generator gas turbine combined heat and power (CHP) system are considered, and recommendations are presented.

  4. Corrosion and Materials Performance in biomass fired and co-fired power plants

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Larsen, OH; Biede, O

    2003-01-01

    not previously encountered in coal-fired power plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. In woodchip boilers, a similar corrosion rate and corrosion mechanism has on some occasions been observed. Co-firing of straw (10...... and 20% energy basis) with coal has shown corrosion rates lower than those in straw-fired plants. With both 10 and 20% straw, no chlorine corrosion was seen. This paper will describe the results from in situ investigations undertaken in Denmark on high temperature corrosion in biomass fired plants....... Results from 100% straw-firing, woodchip and co-firing of straw with coal will be reported. The corrosion mechanisms observed are summarized and the corrosion rates for 18-8 type stainless steels are compared....

  5. Biomass co-firing under oxy-fuel conditions

    DEFF Research Database (Denmark)

    Álvarez, L.; Yin, Chungen; Riaza, J.;

    2014-01-01

    to have favourable synergy effects in all the cases: it significantly improves the burnout and remarkably lowers NOx emissions. The reduced peak temperatures during co-firing can also help to mitigate deposition formation in real furnaces. Co-firing CO2-neutral biomass with coals under oxy-fuel conditions...... can achieve a below-zero CO2 emission if the released CO2 is captured and sequestered. The model-predicted burnout and gaseous emissions were compared against the experimental results. A very good agreement was observed, the differences in a range of ± 5–10% of the experimental values, which indicates...

  6. Analysis of biomass co-firing systems in Taiwan power markets using linear complementarity models

    International Nuclear Information System (INIS)

    Biomass co-firing systems in power plants generate electric power by the simultaneous combustion of biomass and fossil fuels. The co-firing process reduces investment costs by converting biomass energy into electricity in existing conventional power plants. Biomass co-firing significantly reduces carbon dioxide and sulfur dioxide emissions in power generation. To meet the increase in biomass demand, this paper has considered systematic energy crop production, which is expected to increase in the near future. Our aim is to analyze biomass co-firing systems in the Taiwanese electricity market. In this paper, we study two emerging biomass feedstocks: switchgrass and Miscanthus. We focus on the impact of energy crop co-firing on carbon dioxide and sulfur dioxide emissions for electricity generation. A Nash-Cournot competition model, which simulates potential biomass co-firing scenarios, is formulated for power markets. A case study conducted in the Taiwanese electricity market showed that biomass co-firing lowers total electricity demand and sale. Miscanthus is more economical than switchgrass in terms of the production cost and the land required to generate biopower for the same levels of biomass co-firing. - Highlights: → Biomass co-firing system in electricity market is analyzed in this paper. → The research studies the impact of two energy crops in co-firing system. → This paper conducts a case study of co-firing system in Taiwan power markets.

  7. Switching to biomass co-firing in European coal power plants: Estimating the biomass and CO 2 breakeven prices

    OpenAIRE

    Bertrand, Vincent

    2013-01-01

    This paper investigates the cost of biomass co-firing in European coal power stations. We propose a tractable and original method, that enables us to get expressions of biomass and CO2 breakeven points for co-firing in different types of coal plants. We call them carbon switching price and biomass switching price. They correspond to carbon and biomass prices that make coal plants equally attractive under co-firing or classical conditions (i.e. when coal is the only input). The carbon switchin...

  8. Thermodynamic Analyses of Biomass Gasification Integrated Externally Fired, Post-Firing and Dual-Fuel Combined Cycles

    Directory of Open Access Journals (Sweden)

    Saeed Soltani

    2015-01-01

    Full Text Available In the present work, the results are reported of the energy and exergy analyses of three biomass-related processes for electricity generation: the biomass gasification integrated externally fired combined cycle, the biomass gasification integrated dual-fuel combined cycle, and the biomass gasification integrated post-firing combined cycle. The energy efficiency for the biomass gasification integrated post-firing combined cycle is 3% to 6% points higher than for the other cycles. Although the efficiency of the externally fired biomass combined cycle is the lowest, it has an advantage in that it only uses biomass. The energy and exergy efficiencies are maximized for the three configurations at particular values of compressor pressure ratios, and increase with gas turbine inlet temperature. As pressure ratio increases, the mass of air per mass of steam decreases for the biomass gasification integrated post-firing combined cycle, but the pressure ratio has little influence on the ratio of mass of air per mass of steam for the other cycles. The gas turbine exergy efficiency is the highest for the three configurations. The combustion chamber for the dual-fuel cycle exhibits the highest exergy efficiency and that for the post-firing cycle the lowest. Another benefit of the biomass gasification integrated externally fired combined cycle is that it exhibits the highest air preheater and heat recovery steam generator exergy efficiencies.

  9. Deactivation of V2O5-WO3-TiO2 SCR catalyst at a biomass-fired combined heat and power plant

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker; Johnsson, Jan Erik

    2005-01-01

    The deactivation of a commercial type V2O5-WO3-TiO2 monolith catalyst under biomass combustion was studied at a full-scale grate-fired power plant burning straw/wood using a slip stream pilot scale reactor. The aerosols in the flue gas consisted of a mixture of potassium chloride and sulphate. Th...... though reactivation is possible, the deactivation rate appears too high for practical use of the SCR process in straw combustion....

  10. Numerical study of co-firing pulverized coal and biomass inside a cement calciner.

    Science.gov (United States)

    Mikulčić, Hrvoje; von Berg, Eberhard; Vujanović, Milan; Duić, Neven

    2014-07-01

    The use of waste wood biomass as fuel is increasingly gaining significance in the cement industry. The combustion of biomass and particularly co-firing of biomass and coal in existing pulverized-fuel burners still faces significant challenges. One possibility for the ex ante control and investigation of the co-firing process are computational fluid dynamics (CFD) simulations. The purpose of this paper is to present a numerical analysis of co-firing pulverized coal and biomass in a cement calciner. Numerical models of pulverized coal and biomass combustion were developed and implemented into a commercial CFD code FIRE, which was then used for the analysis. Three-dimensional geometry of a real industrial cement calciner was used for the analysis. Three different co-firing cases were analysed. The results obtained from this study can be used for assessing different co-firing cases, and for improving the understanding of the co-firing process inside the calculated calciner.

  11. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    OpenAIRE

    Marc A. Rosen; Shoaib Mehmood; Bale V. Reddy

    2012-01-01

    The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel) and two coals (bituminous coal and lignite) are considered. Key system performance parameters are evaluated for various fuel combina...

  12. Combating corrosion in biomass and waste-fired plant

    OpenAIRE

    Henderson, Pamela; Hjörnhede, Anders

    2010-01-01

    Many biomass- or waste-fired plants have problems with high temperature corrosion especially if the steam temperature is greater than500°C.  An increase in the combustion of waste fuels means that an increasing number of boilers have had problems. Therefore, there is great interest in reducing the costs associated with high temperature corrosion and at the same time there exists a desire to improve the electrical efficiency of a plant by the use of higher steam temperatures.  Assuming that th...

  13. Gas turbines: gas cleaning requirements for biomass-fired systems

    Directory of Open Access Journals (Sweden)

    Oakey John

    2004-01-01

    Full Text Available Increased interest in the development of renewable energy technologies has been hencouraged by the introduction of legislative measures in Europe to reduce CO2 emissions from power generation in response to the potential threat of global warming. Of these technologies, biomass-firing represents a high priority because of the modest risk involved and the availability of waste biomass in many countries. Options based on farmed biomass are also under development. This paper reviews the challenges facing these technologies if they are to be cost competitive while delivering the supposed environmental benefits. In particular, it focuses on the use of biomass in gasification-based systems using gas turbines to deliver increased efficiencies. Results from recent studies in a European programme are presented. For these technologies to be successful, an optimal balance has to be achieved between the high cost of cleaning fuel gases, the reliability of the gas turbine and the fuel flexibility of the overall system. Such optimisation is necessary on a case-by-case basis, as local considerations can play a significant part.

  14. Combating corrosion in biomass and waste fired plant

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Pamela [Vattenfall AB, Stockholm (Sweden). Research and Development; Hjoernhede, Anders [Vattenfall AB, Gothenburg (Sweden). Power Consultant

    2010-07-01

    Many biomass- or waste-fired plants have problems with high temperature corrosion especially if the steam temperature is greater than 500 C. An increase in the combustion of waste fuels means that an increasing number of boilers have had problems. Therefore, there is great interest in reducing the costs associated with high temperature corrosion and at the same time there exists a desire to improve the electrical efficiency of a plant by the use of higher steam temperatures. Assuming that the fuel is well-mixed and that there is good combustion control, there are in addition a number of other measures which can be used to reduce superheater corrosion in biomass and waste fired plants, and these are described in this paper. These include the use of fuel additives, specifically sulphur-containing ones; design aspects like placing superheaters in less corrosive positions in a boiler, using tube shielding, a wider pitch between the tubes; operational considerations such as more controlled soot-blowing and the use of better materials. (orig.)

  15. Comparative life cycle assessment of biomass co-firing plants with carbon capture and storage

    NARCIS (Netherlands)

    Schakel, Wouter; Meerman, Hans; Talaei, Alireza; Ramírez, Andrea; Faaij, André

    2014-01-01

    Combining co-firing biomass and carbon capture and storage (CCS) in power plants offers attractive potential for net removal of carbon dioxide (CO2) from the atmosphere. In this study, the impact of co-firing biomass (wood pellets and straw pellets) on the emission profile of power plants with carbo

  16. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2007-01-01

    Over the past years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore to combat chloride corrosion problems co-firing of biomass with a fossil fuel has been undertaken...... significant corrosion attack was due to sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels are discussed....... appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 hours using 0-20% straw co-firing with coal, the plant now runs with a fuel of 10% straw + coal. After three years exposure in this environment...

  17. Characteristics of smoke emissions from biomass fires of the Amazon region - BASE-A experiment

    Science.gov (United States)

    Ward, Darold E.; Setzer, Alberto W.; Kaufman, Yoram J.; Rasmussen, Rei A.

    1991-01-01

    The Biomass Burning Airborne and Spaceborne Experiment-Amazonia was designed for study of both aerosol and gaseous emissions from fires using an airborne sampling platform. The emission factors for combustion products from four fires suggest that the proportion of carbon released in the form of CO2 is higher than for fires of logging which has been burned in the western U.S. Combustion efficiency was of the order of 97 percent for the Amazonian test fire and 86-94 percent for deforestation fires. The inorganic content of particles from tropical fires are noted to be different from those of fires in the U.S.

  18. Recommendations for conversions of grate fired boilers to fluidising beds; Anvisningar foer konvertering av rosterpannor till fluidiserad baeddteknik

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Lars; Ingman, Rolf [AaF Energikonsult AB, Stockholm (Sweden)

    2001-03-01

    This report gives advice and recommendations for retrofitting of grate fired boilers to fluidising beds. Nine plants have been visited and experiences from these conversion projects have been gathered and analysed. Among the important points planning, fuel specification, heat balance calculations and clarifying of delivery limits can be mentioned. It is also important not to underestimate the need for education of the operational staff.

  19. BENEFIT COST FOR BIOMASS CO-FIRING IN ELECTRICITY GENERATION: CASE OF UTAH, U.S.

    Directory of Open Access Journals (Sweden)

    Man-Keun Kim

    2015-07-01

    Full Text Available Policy making regarding biomass co-firing is difficult. The article provides a benefit-cost analysis for decision makers to facilitate policy making process to implement efficient biomass co-firing policy. The additional cost is the sum of cost of the biomass procurement and biomass transportation. Co-benefits are sales of greenhouse gas emission credits and health benefit from reducing harmful air pollutants, especially particulate matter. The benefit-cost analysis is constructed for semi-arid U.S. region, Utah, where biomass supply is limited. Results show that biomass co-firing is not economically feasible in Utah but would be feasible when co-benefits are considered. Benefit-cost ratio is critically dependent upon biomass and carbon credit prices. The procedure to build the benefit-cost ratio can be applied for any region with other scenarios suggested in this study.

  20. Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power

    Directory of Open Access Journals (Sweden)

    J. W. Kaiser

    2011-07-01

    Full Text Available The Global Fire Assimilation System (GFASv1.0 calculates biomass burning emissions by assimilating Fire Radiative Power (FRP observations from the MODIS instruments onboard the Terra and Aqua satellites. It corrects for gaps in the observations, which are mostly due to cloud cover, and filters spurious FRP observations of volcanoes, gas flares and other industrial activity. The combustion rate is subsequently calculated with land cover-specific conversion factors. Emission factors for 40 gas-phase and aerosol trace species have been compiled from a literature survey. The corresponding daily emissions have been calculated on a global 0.5° × 0.5° grid from 2003 to the present. General consistency with the Global Fire Emission Database version 3.1 (GFED3.1 within its accuracy is achieved while maintaining the advantages of an FRP-based approach: GFASv1.0 makes use of the quantitative information on the combustion rate that is contained in the observations, and it detects fires in real time at high spatial and temporal resolution. GFASv1.0 indicates omission errors in GFED3.1 due to undetected small fires. It also exhibits slightly longer fire seasons in South America and North Africa and a slightly shorter fire season in Southeast Asia. GFASv1.0 has already been used for atmospheric reactive gas simulations in an independent study, which found good agreement with atmospheric observations. We have performed simulations of the atmospheric aerosol distribution with and without the assimilation of MODIS aerosol optical depth (AOD. They indicate that the emissions of particulate matter need to be boosted with a factor of 2–4 to reproduce the global distribution of organic matter and black carbon. This discrepancy is also evident in the comparison of previously published top-down and bottom-up estimates. For the time being, a global enhancement of the particulate matter emissions by 3.4 is recommended. Validation with independent AOD and PM10

  1. Characterization and Quantification of Deposits Buildup and Removal in Biomass Suspension-Fired Boilers

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    2010-01-01

    uptake reduction, fly ash and deposit characteristics, and deposit removal by using an advanced online deposit probe in a suspension­fired boiler using wood and straw pellets as fuel. The influence of fuel type and probe exposure time on the ash deposition rate, the heat uptake, the fly ash and deposit...... small in the tube bank region (flue gas temperature, 550­605 oC) during pure wood­firing. It was found that during suspension­firing of pure straw at low boiler load, the overall weight uptake is comparable with grate­firing, even though the amount of fly ash generated was significantly higher during...

  2. Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust

    Science.gov (United States)

    Bellmann, B.; Creutzenberg, O.; Ernst, H.; Muhle, H.

    2009-02-01

    The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentration of 16 mg/m3. The MMAD of all fly ash samples and reference materials in the inhalation unit were in the range from 1.5 to 3 μm. The investigations focused predominantly on the analysis of inflammatory effects in the lungs of rats using bronchoalveolar lavage (BAL) and histopathology. Different parameters (percentage of polymorphonuclear neutrophils (PMN), interleukin-8 and interstitial inflammatory cell infiltration in the lung tissue) indicating inflammatory effects in the lung, showed a statistically significant increase in the groups exposed to carbon black (positive control), C1 (coal) and C1+BM4 (co-firing of coal and sawdust) fly ashes. Additionally, for the same groups a statistically significant increase of cell proliferation in the lung epithelium was detected. No significant effects were detected in the animal groups exposed to BM1 (bark), BM2 (wood chips), BM3 (waste wood), BM6 (straw) or titanium dioxide.

  3. Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust

    International Nuclear Information System (INIS)

    The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentration of 16 mg/m3. The MMAD of all fly ash samples and reference materials in the inhalation unit were in the range from 1.5 to 3 μm. The investigations focused predominantly on the analysis of inflammatory effects in the lungs of rats using bronchoalveolar lavage (BAL) and histopathology. Different parameters (percentage of polymorphonuclear neutrophils (PMN), interleukin-8 and interstitial inflammatory cell infiltration in the lung tissue) indicating inflammatory effects in the lung, showed a statistically significant increase in the groups exposed to carbon black (positive control), C1 (coal) and C1+BM4 (co-firing of coal and sawdust) fly ashes. Additionally, for the same groups a statistically significant increase of cell proliferation in the lung epithelium was detected. No significant effects were detected in the animal groups exposed to BM1 (bark), BM2 (wood chips), BM3 (waste wood), BM6 (straw) or titanium dioxide.

  4. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2008-01-01

    Over the past few years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore, to combat chloride corrosion problems cofiring of biomass with a fossil fuel has been....... However, the most significant corrosion attack was sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels...... corrosion mechanisms appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 h using 0–20% straw co-firing with coal, the plant now runs with a fuel mix of 10% strawþcoal. Based on results from a 3 years exposure...

  5. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-03-01

    Full Text Available The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel and two coals (bituminous coal and lignite are considered. Key system performance parameters are evaluated for various fuel combinations and co-firing ratios, using a system model and numerical simulation. The results indicate that plant energy efficiency decreases with increase of biomass proportion in the fuel mixture, and that the extent of the decrease depends on specific properties of the coal and biomass types.

  6. Emissions and Furnace Gas Temperature for Electricity Generation Via Co-Firing of Coal and Biomass

    OpenAIRE

    Shoaib Mehmood; Bale Reddy; Marc Rosen

    2015-01-01

    The emissions of carbon dioxide and nitrogen and sulphur oxides for electricity generation with coal and biomass co-firing are investigated and the furnace gas temperature assessed. The study uses simulation and considers fuel combinations based on two coals (bituminous coal, lignite) and four types of biomass (rice husk, sawdust, chicken litter, refused derived fuel). With increasing biomass, net CO2 emissions are seen to decline significantly for all types of selected biomass, while gross c...

  7. Additive for reducing operational problems in waste fired grate boilers; Additiv foer att minska driftproblem vid rostfoerbraenning av avfall

    Energy Technology Data Exchange (ETDEWEB)

    Gyllenhammar, Marianne; Herstad Svaerd, Solvie; Davidsson, Kent; Hermansson, Sven; Liske, Jesper; Larsson, Erik; Jonsson, Torbjoern; Zhao, Dongmei

    2013-09-01

    The combustion of waste implies a risk for deposits and corrosion in different parts of the combustion facility. In recent years, research and tests have been performed in order to find ways to mitigate these problems in waste-fired plants. Most waste-fired plants in Sweden are grates whereas most of the research has been carried out in fluidized bed plants. The purpose of this project is to examine whether co-firing of sewage sludge and waste can reduce deposition and corrosion also in grate-fired boilers as has been shown in fludised beds. The objective is to determine the deposit growth and its composition as well as describing the initial corrosion attack. Representing sulphur-rich waste, elementary sulphur is also added to the waste and thereby compared with sludge as an additive. The target groups for this project are plant owners, researchers, consultants and authorities. Tests were performed in a 15 MWth waste-fired boiler with moving grate at Gaerstadverket, Tekniska Verken (Linkoeping). The boiler produces saturated steam of 17 bars and 207 deg C, and the normal fuel mixture contains of household and industry waste. The results show that co-firing with as heigh as 20 weight-% SLF (25 energy-%) was possible from an operational point of view, but the deposit rate increased especially at the two warmest positions. Generally the deposit rate was highest in the position closest to the boiler and decreased further downstream. During the tests a lot higher amount of SLF than normal was used (recommended mix is 5-10 % of SLF) this to be able to see effects of the different measures. Up to 23 weight-% of the rather moist sewage sludge was possible to fire when co-firing waste and SLF, without addition of oil. By adding sludge the deposit rate decreased but the increase upon adding SLF to ordinary waste was not totally eliminated. In the tests 'Avfall and SLF' the deposits were rich in chlorine. High concentrations of metal chlorides were found in the

  8. Biomass integrated gasification combined cycle power generation with supplementary biomass firing: Energy and exergy based performance analysis

    International Nuclear Information System (INIS)

    A thermodynamic analysis of a Biomass Integrated Gasification Combined Cycle (BIGCC) plant has been performed based on energy and exergy balances in a proposed configuration. Combustion of supplementary biomass fuel is considered using the oxygen available in the gas turbine (GT) exhaust. The effects of pressure and temperature ratios of the GT system and the amount of fuel burned in the supplementary firing chamber on the thermal and exergetic efficiencies of the plant have been investigated. The plant efficiencies increase with the increase in both pressure and temperature ratios; however, the latter has a stronger influence than the former. Supplementary firing of biomass increases the plant efficiencies of a BIGCC plant till an optimum level of degree of firing. The other technical issues related to supplementary firing, like ash fusion in the furnace and exhaust heat loss maintaining a minimum pinch point temperature difference are accounted and finally a set of optimum plant operating parameters have been identified. The performance of a 50 MWe plant has been analyzed with the optimum operating parameters to find out equipment rating and biomass feed rates. Exergetic efficiencies of different plant equipments are evaluated to localize the major thermodynamic irreversibilities in the plant. -- Highlights: → A thermodynamic analysis of a Biomass Integrated Gasification Combined Cycle (BIGCC) plant has been performed based on energy and exergy balances across various plant components in a proposed configuration in order to optimize the operating parameters. → The effect of supplementary biomass firing in the BIGCC plant has been analyzed in detail to find out the optimum degree of firing for the best plant performance. → The equipment ratings and fuel feed rates are evaluated and the technical feasibility of the plant configuration has been analyzed. → Exergetic efficiencies of different plant equipments are evaluated to localize the major thermodynamic

  9. Co-firing in coal power plants and its impact on biomass feedstock availability

    International Nuclear Information System (INIS)

    Several states have a renewable portfolio standard (RPS) and allow for biomass co-firing to meet the RPS requirements. In addition, a federal renewable fuel standard (RFS) mandates an increase in cellulosic ethanol production over the next decade. This paper quantifies the effects on local biomass supply and demand of different co-firing policies imposed on 398 existing coal-fired power plants. Our model indicates which counties are most likely to be able to sustain cellulosic ethanol plants in addition to co-firing electric utilities. The simulation incorporates the county-level biomass market of corn stover, wheat straw, switchgrass, and forest residues as well as endogenous crop prices. Our scenarios indicate that there is sufficient feedstock availability in Southern Minnesota, Iowa, and Central Illinois. Significant supply shortages are observed in Eastern Ohio, Western Pennsylvania, and the tri-state area of Illinois, Indiana, and Kentucky which are characterized by a high density of coal-fired power plants with high energy output. - Highlights: • Co-firing in coal-power plants can lead to biomass supply shortage. • The level of shortage depends also on the switchgrass production cost. • Little to no shortages occur in the Corn Belt and the Great Plains. • Biomass co-firing in power plants limits the supply for cellulosic ethanol plants

  10. The feasibility of co-firing biomass for electricity in Missouri

    International Nuclear Information System (INIS)

    Bioenergy is one of the most significant energy resources with potential to serve as a partial replacement for fossil. As an agricultural state, Missouri has great potential to use biomass for energy production. In 2008, Missouri adopted a renewable portfolio standard (RPS) yet about 80% of its power supply still comes from coal. This paper describes a feasibility study of co-firing biomass in existing coal-powered plants in Missouri. Specifically, this study developed a linear programming model and simulated six scenarios to assess the economic feasibility and greenhouse gas impacts of co-firing biomass in existing qualified coal power plants in Missouri. The results of this study indicate that although co-firing can reduce the emissions of GHG and environmental pollutants, it is still not an economically feasible option for power generation without additional economic or policy incentives or regulations which could take environmental costs into account. Based on these results, strategies and policies to promote the utilization of biomass and to increase its competitiveness with fossil fuels are identified and discussed. - Highlights: • This paper reports on a study of the economic feasibility and environmental effects of co-firing biomass for electricity. • The feasibility of co-firing biomass varies by location depending on local availability of biomass and size of facility. • We apply a linear optimization model that generates economic and environmental indicators for each of several locations. • This paper will appeal to power generators, academic researchers and consultants interested in the feasibility of biopower

  11. Three-dimensional computer simulation for combustion and NO{sub x} emission in a grate fired boiler at Baeckhamars, Sweden. Technical report[(Baeckhammars Bruk)

    Energy Technology Data Exchange (ETDEWEB)

    Dong Wei [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Metallurgy

    2000-05-01

    This report describes the fundament of mathematical modeling for the grate fired boilers in Part A, and presents the results from the numerical simulations for the flow pattern, combustion and NO{sub x} emission in the Baeckhammars grate fired boiler in Part B. The simulated boiler is equipped with a new secondary air supply system called Ecotube. The objective of this project is to develop and experimentally verify tools for computer simulations of solid biomass fuel combustion processes in a grate fired boiler. The work focuses on the numerical simulation using CFD technique and development of a NO{sub x} post processor. The unstructured mesh technique also has been used to discretize the boiler. An unstructured grid with total 284399 tetrahedral cells describes the three dimensional geometry and is used for flow field and combustion simulations. In order to simulate the combustion process in the boiler, a simplified grate bed model -- black-box bed model is used, which is based on the balance analysis of mass and energy on the grate bed and needless to consider any detailed and very difficult dynamic processes which have not been valuable by mathematical modeling on the grate bed yet. Therefore, it is quite convenient for industrial applications. In this work, both the cyanide route and the ammonia route for modeling the fuel containing nitrogen NO{sub x} are developed, and the former has been used to predict the NO generation in Baeckhammars bark boiler. Two 3D cases corresponding to 15 MW and 11 MW output thermal power respectively are simulated in detail. Results show that a new air supply system called Ecotube gives a considerably more uniform velocity, temperature and concentration distribution from the secondary air tubes to the upper part of the furnace. The upper furnace works almost as a 'plug flow reactor' which gives sufficient residence time for CO conversion and low NO{sub x} emission. The calculations of flow and mixing patterns in the

  12. Co-firing of Coal with Biomass and Waste in Full-scale Suspension-fired Boilers

    DEFF Research Database (Denmark)

    Dam-Johansen, Kim; Jappe Frandsen, Flemming; Jensen, Peter Arendt;

    2013-01-01

    -based suspension-fired boilers to accept still higher fractions of biomass or waste material as fuels. This last development has been challenging of many reasons, including pre-treatment of fuels, and solving potential emission and operational problems during the simultaneous development of supercritical steam...

  13. China - Biomass Cogeneration Development Project : Fuel Supply Handbook for Biomass-Fired Power Projects

    OpenAIRE

    World Bank

    2010-01-01

    This handbook provides an overview of the main topics that need consideration when managing the supply of biomass to large biomass power plants. It will help investors in China to develop, with assistance of local biomass supply experts, their own solutions. The focus is on biomass residues, in particular agricultural residues (mainly straw and stalks) and forestry residues (mainly residue...

  14. Global burned area and biomass burning emissions from small fires

    NARCIS (Netherlands)

    Randerson, J.T; Chen, Y.; Werf, van der G.R.; Rogers, B.M.; Morton, D.C.

    2012-01-01

    [1] In several biomes, including croplands, wooded savannas, and tropical forests, many small fires occur each year that are well below the detection limit of the current generation of global burned area products derived from moderate resolution surface reflectance imagery. Although these fires ofte

  15. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Kalyan Annamalai; Dr. John Sweeten; Dr. Sayeed Mukhtar

    2000-10-24

    The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Order has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to generate base line data followed by methane, feedlot and litter biomass fuels.

  16. Emissions and Furnace Gas Temperature for Electricity Generation Via Co-Firing of Coal and Biomass

    Directory of Open Access Journals (Sweden)

    Shoaib Mehmood

    2015-12-01

    Full Text Available The emissions of carbon dioxide and nitrogen and sulphur oxides for electricity generation with coal and biomass co-firing are investigated and the furnace gas temperature assessed. The study uses simulation and considers fuel combinations based on two coals (bituminous coal, lignite and four types of biomass (rice husk, sawdust, chicken litter, refused derived fuel. With increasing biomass, net CO2 emissions are seen to decline significantly for all types of selected biomass, while gross carbon dioxide emissions increase for all blends except bituminous coal/refuse derived fuel, lignite/chicken litter and lignite/refuse derived fuel. The reductions in emissions of nitrogen and sulphur oxides are dependent on the contents of nitrogen and sulphur in the biomass. The results also show for all fuel combinations that increasing the biomass proportion decreases the furnace exit gas temperature.

  17. Co-firing fossil fuels and biomass: combustion, deposition and modelling

    OpenAIRE

    Khodier, Ala H. M.

    2011-01-01

    The application of advanced technologies employing combustion/co-firing of coal and biomass is seen as a promising approach to minimising the environmental impact and reducing CO2 emissions of heat/power production. The existing uncertainties in the combustion behaviour of such fuel mixes and the release of alkali metals with other elements during the combustion (or co-firing) of many bio-fuels are some of the main issues that are hindering its application. The potential presen...

  18. Thermodynamic analysis of a biomass-fired Kalina cycle with regenerative heater

    International Nuclear Information System (INIS)

    The biomass fuel is a renewable energy resource, which is viewed as a promising alternative to fossil energy. This paper investigates a biomass-fired Kalina cycle with a regenerative heater which is generally utilized to heat the feedwater and to increase the efficiency in coal-fired steam power plant. The mathematical model of the biomass-fired Kalina cycle with a regenerative heater is established to conduct numerical simulation. A parametric analysis is conducted to examine the effects of some key thermodynamic parameters on the system performance. Furthermore, a parametric optimization is carried out by genetic algorithm to obtain the optimum performance of system. The results demonstrate that there exists an optimum extraction pressure and its corresponding maximum fraction of flow extracted from turbine to maximize the net power output and system efficiency. In addition, a higher turbine inlet pressure or turbine inlet temperature leads to higher net power output and system efficiency. And net power output and system efficiency increases as separator temperature rises. The optimization result of the biomass-fired Kalina cycle with/without regenerative heater indicates the system is more efficient when regenerative heater is added. - Highlights: • Kalina cycle with a regenerative heater is driven by biomass boiler. • The effects of several parameters on system performance are examined. • Parametric optimization is conducted by GA to obtain optimum performance

  19. High Temperature Corrosion in Biomass-Fired Boilers

    DEFF Research Database (Denmark)

    Henriksen, Niels; Montgomery, Melanie; Hede Larsen, Ole

    2002-01-01

    condense on superheater components. This gives rise to specific corrosion problems not previously encountered in coal-fired power plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. To avoid such high corrosion rates, woodchip...... has also been utilised as a fuel. Combustion of woodchip results in a smaller amount of ash, and potassium and chlorine are present in lesser amounts. However, significant corrosion rates were still seen. A case study of a woodchip fired boiler is described. The corrosion mechanisms in both straw...

  20. SEM Investigation of Superheater Deposits from Biomass-Fired Boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt; Frandsen, Flemming; Hansen, Jørn;

    2004-01-01

    , mature superheater deposit samples were extracted from two straw-fired boilers, Masnedø and Ensted, with fuel inputs of 33 MWth and 100 MWth, respectively. SEM (scanning electron microscopy) images and EDX (energy dispersive X-ray) analyses were performed on the deposit samples. Different strategies...

  1. High temperature corrosion under conditions simulating biomass firing: depth-resolved phase identification

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming;

    2014-01-01

    Both cross-sectional and plan view, ‘top-down’ characterization methods were employed , for a depth-resolved characterization of corrosion products resulting from high temperature corrosion under laboratory conditions simulating biomass firing. Samples of an austenitic stainless steel (TP 347H FG...

  2. Application of remote sensing to understanding fire regimes and biomass burning emissions of the tropical Andes

    NARCIS (Netherlands)

    Oliveras Menor, I.; Anderson, L.O.; Malhi, Y.

    2014-01-01

    In the tropical Andes, there have been very few systematic studies aimed at understanding the biomass burning dynamics in the area. This paper seeks to advance on our understanding of burning regimes in this region, with the first detailed and comprehensive assessment of fire occurrence and the deri

  3. Effect of Water Vapor on High-Temperature Corrosion under Conditions Mimicking Biomass Firing

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming;

    2015-01-01

    The variable flue gas composition in biomass-fired plants, among other parameters, contributes to the complexityof high-temperature corrosion of materials. Systematic parameter studies are thus necessary to understand the underlyingcorrosion mechanisms. This paper investigates the effect of water...

  4. Alkali chloride induced corrosion of superheaters under biomass firing conditions: Improved insights from laboratory scale studies

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming;

    2015-01-01

    One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed to the fo...

  5. Physical characterization of biomass fuels prepared for suspension firing in utility boilers for CFD modelling

    DEFF Research Database (Denmark)

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

    2007-01-01

    shapes. The sample is subdivided by straw type, and coherent size, type and mass distribution parameters are reported for the entire sample. This type of data is necessary in order to use CFD reliably as a design and retrofit tool for co-firing biomass with fossil fuels, as the combustion processes...

  6. ASEAN grid-connected biomass residues fired cogeneration plants

    International Nuclear Information System (INIS)

    Energy supply is one of the major concerns in the world. With uncertainty in the main oil suppliers, the oil price is expected to remain high due to continuous demand from the world. Since oil is mostly used for electricity and transportation, its shortage would cause major disruptions in our daily activities. Thus to counter this scenario and faster depletion of fossil fuel resources, various measures have been taken to find alternative source of energy such as renewable energy. One of the renewable energy sources is from biomass residues which is aplenty particularly in ASEAN. Through one of the collaboration programme between ASEAN and EC which is The EC-ASEAN Cogeneration Programme, a number of Full-Scale Demonstration Projects (FSDP) using biomass residues have been commissioned and implemented successfully. Four of the FSDPs in Thailand and Malaysia are connected to the grid. These projects have been operating very well and since the fuel is commonly available in this ASEAN region, duplication should not be a problem. Thus, this paper would highlight the success stories in implementing biomass residues grid connected project while enhancing cooperation between ASEAN and EC. (Author)

  7. Vegetation fires, absorbing aerosols and smoke plume characteristics in diverse biomass burning regions of Asia

    International Nuclear Information System (INIS)

    In this study, we explored the relationships between the satellite-retrieved fire counts (FC), fire radiative power (FRP) and aerosol indices using multi-satellite datasets at a daily time-step covering ten different biomass burning regions in Asia. We first assessed the variations in MODIS-retrieved aerosol optical depths (AOD’s) in agriculture, forests, plantation and peat land burning regions and then used MODIS FC and FRP (hereafter FC/FRP) to explain the variations in AOD characteristics. Results suggest that tropical broadleaf forests in Laos burn more intensively than the other vegetation fires. FC/FRP-AOD correlations in different agricultural residue burning regions did not exceed 20% whereas in forest regions they reached 40%. To specifically account for absorbing aerosols, we used Ozone Monitoring Instrument-derived aerosol absorption optical depth (AAOD) and UV aerosol index (UVAI). Results suggest relatively high AAOD and UVAI values in forest fires compared with peat and agriculture fires. Further, FC/FRP could explain a maximum of 29% and 53% of AAOD variations, whereas FC/FRP could explain at most 33% and 51% of the variation in agricultural and forest biomass burning regions, respectively. Relatively, UVAI was found to be a better indicator than AOD and AAOD in both agriculture and forest biomass burning plumes. Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations data showed vertically elevated aerosol profiles greater than 3.2–5.3 km altitude in the forest fire plumes compared to 2.2–3.9 km and less than 1 km in agriculture and peat-land fires, respectively. We infer the need to assimilate smoke plume height information for effective characterization of pollutants from different sources. (letter)

  8. Feedlot biomass co-firing: a renewable energy alternative for coal-fired utilities. Paper no. IGEC-1-128

    International Nuclear Information System (INIS)

    The swiftly growing feedlot industry in the United States upshots in the production of manure from one or more animal species in excess of what can safely be applied to farmland in accordance with nutrient management plans. Disposal of the vast quantity of manure produced as a by-product of the cattle feeding industry is one of the major operating tasks of the industry. Aside from the traditional means of disposal as fertilizer, an alternative and attractive way of overcoming this threat is to develop processes that make use of manure as an energy resource. In the present study, the feasibility of using of manure as a fuel in existing coal fired power plants is considered and appropriately termed Feedlot Biomass (FB). The technology of co-firing coal: feedlot biomass facilitates an environment friendly utilization of animal waste for the production of valuable power/steam concurrently addressing the renewable energy, groundwater contamination, and greenhouse gas concerns. Co-firing tests were performed at the Texas AandM University 30 kWt (100,000 Btu/h) laboratory-scale facility. The trials revealed the enhanced combustion of the blends. The NO emissions were less for the blend even with higher nitrogen content of FB as compared to coal. (author)

  9. Fire and man - reconstructing Holocene biomass burning in the central European lowlands

    Science.gov (United States)

    Dietze, Elisabeth; Słowiński, Michał; Feurdean, Angelica; Dräger, Nadine; Obremska, Milena; Ott, Florian; Pieńczewska, Anna; Theuerkauf, Martin; Brauer, Achim

    2016-04-01

    Fire is an important earth surface process that interacts with climate and vegetation and influences global biogeochemical cycles and carbon budget. Moreover, fire is tightly connected to the evolution and distributions of human beings. Especially in the humid vegetation zones that naturally do not inflame easily, fire has been the major tool to convert forests to arable land. In the central European lowlands, naturally dominated by broad-leaved forests, palaeofires were strongly related to human impact during at least the last 6000 years. Hence, the detection of past biomass burning in the sedimentological record points to human activity. Charcoal (black carbon) is the classical and widely-used proxy to reconstruct past fire histories. Abundant sedimentary charcoal records exist around the globe, and many are included in the Global Charcoal Database (GCD, www.gpwg.org). Molecular fire markers, on the other hand, are now being developed as new proxies to detect past biomass burning. This study reviews classical and "new" fire-proxies in peat and lake sediments that allow to reconstruct the signals of human impact on a regional scale in the central European lowlands with high temporal resolution. Furthermore, the charcoal records from the GCD and other sources covering the central European lowlands and adjacent areas were integrated in a spatial synthesis to document the current state-of-knowledge on regional Holocene fire history. We show preliminary charcoal data from the annually-laminated sediments of lakes Tiefer See (northeastern Germany) and Czechowskie (northern Poland). Links to reconstructed local and European-wide vegetation successions will be provided, as in times with dry climate and the dominance of a certain fire-prone vegetation cover (e.g., Pinus spec.), wildfires might have played a further important role. However, the interpretation of charcoal records is not always straightforward. Hence, we also discuss the potentials of other palaeofire

  10. Use of numerical modeling in design for co-firing biomass in wall-fired burners

    DEFF Research Database (Denmark)

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

    2004-01-01

    of numerical modeling. The models currently used to predict solid fuel combustion rely on a spherical particle shape assumption, which may deviate a lot from reality for big biomass particles. A sphere gives a minimum in terms of the surface-area-to-volume ratio, which impacts significantly both motion....... To better model the reaction of biomass particles, the actual particle surface area available and the average oxygen mass flux at particle surface are considered, both of which are shape factor-dependent. (2) The non-spherical biomass particles are simplified as equal-volume spheres, without any...

  11. Trace gas and particle emissions from fires in large diameter and belowground biomass fuels

    Science.gov (United States)

    Bertschi, Isaac; Yokelson, Robert J.; Ward, Darold E.; Babbitt, Ron E.; Susott, Ronald A.; Goode, Jon G.; Hao, Wei Min

    2003-07-01

    We adopt a working definition of residual smoldering combustion (RSC) as biomass combustion that produces emissions that are not lofted by strong fire-induced convection. RSC emissions can be produced for up to several weeks after the passage of a flame front and they are mostly unaffected by flames. Fuels prone to RSC include downed logs, duff, and organic soils. Limited observations in the tropics and the boreal forest suggest that RSC is a globally significant source of emissions to the troposphere. This source was previously uncharacterized. We measured the first emission factors (EF) for RSC in a series of laboratory fires and in a wooded savanna in Zambia, Africa. We report EFRSC for both particles with diameter cyanide. We show that a model used to predict trace gas EF for fires in a wide variety of aboveground fine fuels fails to predict EF for RSC. For many compounds, our EF for RSC-prone fuels from the boreal forest and wooded savanna are very different from the EF for the same compounds measured in fire convection columns above these ecosystems. We couple our newly measured EFRSC with estimates of fuel consumption by RSC to refine emission estimates for fires in the boreal forest and wooded savanna. We find some large changes in estimates of biomass fire emissions with the inclusion of RSC. For instance, the wooded savanna methane EF increases by a factor of 2.5 even when RSC accounts for only 10% of fuel consumption. This shows that many more measurements of fuel consumption and EF for RSC are needed to improve estimates of biomass burning emissions.

  12. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Soyuz Priyadarsan (PhD)

    2003-06-01

    Reburn with animal waste yield NO{sub x} reduction of the order of 70-80%, which is much higher than those previously reported in the literature for natural gas, coal and agricultural biomass as reburn fuels. Further, the NO{sub x} reduction is almost independent of stoichiometry from stoichiometric to upto 10% deficient air in reburn zone. As a first step towards understanding the reburn process in a boiler burner, a simplified zero-dimensional model has been developed for estimating the NO{sub x} reduction in the reburn process using simulated animal waste based biomass volatiles. However the first model does not include the gradual heat up of reburn fuel particle, pyrolysis and char combustion. Hence there is a need for more rigorous treatment of the model with animal waste as reburn fuel. To address this issue, an improved zero-dimensional model is being developed which can handle any solid reburn fuel, along with more detailed heterogeneous char reactions and homogeneous global reactions. The model on ''NO{sub x} Reduction for Reburn Process using Feedlot Biomass,'' incorporates; (a) mixing between reburn fuel and main-burner gases, (b) gradual heat-up of reburn fuel accompanied by pyrolysis, oxidation of volatiles and char oxidation, (c) fuel-bound nitrogen (FBN) pyrolysis, and FBN including both forward and backward reactions, (d) prediction of NO{sub x} as a function of time in the reburn zone, and (e) gas phase and solid phase temperature as a function of time. The fuel bound nitrogen is assumed to be released to the gas phase by two processes, (a) FBN evolution to N{sub 2}, HCN, and NH{sub 3}, and (b) FBN oxidation to NO at the char surface. The formulation has been completed, code has been developed, and preliminary runs have been made to test the code. Note that, the current model does not incorporate the overfire air. The results of the simulation will be compared with the experimental results. During this quarter, three journal and

  13. A better understanding of biomass co-firing by developing an advanced non-spherical particle tracking model

    DEFF Research Database (Denmark)

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

    2004-01-01

    . To better understand biomass co-firing and therefore improve the design for co-firing biomass in wall-fired burners, the most commonly used spherical particle shape assumption is not used here, which may deviate a lot from reality for big biomass particles. A sphere gives a minimum in terms of the surface-area-to-volume......-gradient force. Since the drag and lift forces are both shape factor- and orientation-dependent, coupled particle rotation equations are resolved to update particle orientation. In the reaction of biomass particles, the actual particle surface area available and the average oxygen mass flux at particle surface...... ratio and thus experiences a totally different motion and reaction as a non-spherical particle. Therefore, an advanced non-spherical particle-tracking model is developed to calculate the motion and reaction of nonspherical biomass particles. The biomass particles are assumed as solid or hollow cylinders...

  14. A kinetic study on the potential of a hybrid reaction mechanism for prediction of NOx formation in biomass grate furnaces

    Science.gov (United States)

    Zahirović, Selma; Scharler, Robert; Kilpinen, Pia; Obernberger, Ingwald

    2011-10-01

    This paper presents the verification of a hybrid reaction mechanism (28 species, 104 reactions) by means of a kinetic study with a view to its application for the CFD-based prediction of gas phase combustion and NOx formation in biomass grate furnaces. The mechanism is based on a skeletal kinetic scheme that includes the subsets for H2, CO, NH3 and HCN oxidation derived from the detailed Kilpinen 97 reaction mechanism. To account for the CH4 breakdown two related reactions from the 4-step global mechanism for hydrocarbons oxidation by Jones and Lindstedt were adopted. The hybrid mechanism was compared to the global mechanism and validated against the detailed Kilpinen 97 mechanism. For that purpose plug flow reactor simulations at conditions relevant to biomass combustion (atmospheric pressure, 1200-1600 K) for approximations of the flue gases in a grate furnace at fuel lean and fuel rich conditions were carried out. The hybrid reaction mechanism outperformed the global one at all conditions investigated. The most striking differences obtained in predictions by the hybrid and the detailed mechanism at the residence times prior to ignition were attributed to the simplified description of the CH4 oxidation in the case of the former. The overall agreement regarding both combustion and NOx chemistry between the hybrid and the detailed mechanism was better at fuel lean conditions than at fuel rich conditions. However, also at fuel rich conditions, the agreement was improving with increasing temperature. Moreover, it was shown that an improvement in the prediction of NOx formation by the N-subset of the hybrid reaction mechanism can be achieved by replacing its C-H-O subset with that of the detailed one.

  15. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-03-31

    Proposed activities for quarter 7 (12/15/01-3/14/2002): (1) Incorporation of moisture model into PCGC2 code. Parametric study of moisture effects on flame structure and pollutants emissions in cofiring of coal and Liter Biomass (LB) (Task 4); (2) Use the ash tracer method to determine the combustion efficiency and comparison it to results from gas analysis (Task 2); (3) Effect of swirl on combustion performance (Task 2); (4) Completion of the proposed modifications to the gasifier setup (Task 3); (5) Calibration of the Gas Chromatograph (GC) used for measuring the product gas species (Task 3); and (6) To obtain temperature profiles for different fuels under different operating conditions in the fixed bed gasifier (Task 3).

  16. Deactivation of SCR catalysts in biomass fired power plants

    DEFF Research Database (Denmark)

    Olsen, Brian Kjærgaard

    in such biomass fuels, however, causes enhanced strain on the different equipment in these power plants. One of the affected units is the catalyst for selective catalytic reduction (SCR) of nitrogen oxides, which undergoes accelerated deactivation due to deposition of potassium rich particles and subsequent...... poisoning. The potassium poisoning of commercial vanadia based SCR catalysts have been studied for more than two decades, and a broad understanding have been obtained. However, more detailed information on the overall mechanism of deposition, reaction and transport of potassium, and its function of catalyst...... composition and operating conditions, is not available. The main objective of the work presented in this thesis has been to conduct an in depth investigation of the deactivation mechanism of vanadia based SCR catalysts, when subjected to potassium rich aerosols. It has furthermore been a goal to suggest...

  17. Field test corrosion experiments in Denmark with biomass fuels Part I Straw firing

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, A; Larsen, OH

    2002-01-01

    In Denmark, straw and other types of biomass are used for generating energy in power plants. Straw has the advantage that it is a "carbon dioxide neutral fuel" and therefore environmentally acceptable. Straw combustion is associated with corrosion problems which are not encountered in coal-fired...... plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. A series of field tests have been undertaken in the various straw-fired power plants in Denmark, namely Masnedø, Rudkøbing and Ensted. Three types of exposure were undertaken...

  18. Fire in Ice: Glacial-Interglacial biomass burning in the NEEM ice core

    Science.gov (United States)

    Zennaro, Piero; Kehrwald, Natalie; Zangrando, Roberta; Gambaro, Andrea; Barbante, Carlo

    2014-05-01

    Earth is an intrinsically flammable planet. Fire is a key Earth system process with a crucial role in biogeochemical cycles, affecting carbon cycle mechanisms, land-surface properties, atmospheric chemistry, aerosols and human activities. However, human activities may have also altered biomass burning for thousands of years, thus influencing the climate system. We analyse the specific marker levoglucosan to reconstruct past fire events in ice cores. Levoglucosan (1,6-anhydro-β-D-glucopyranose) is an organic compound that can be only released during the pyrolysis of cellulose at temperatures > 300°C. Levoglucosan is a major fire product in the fine fraction of woody vegetation combustion, can be transported over regional to global distances, and is deposited on the Greenland ice sheet. The NEEM, Greenland ice core (77 27'N, 51 3'W, 2454 masl) documents past fire activity changes from the present back to the penultimate interglacial, the Eemian. Here we present a fire activity reconstruction from both North American and Eurasian sources over the last 120,000 yrs based on levoglucosan signatures in the NEEM ice core. Biomass burning significantly increased over the boreal Northern Hemisphere since the last glacial, resulting in a maximum between 1.5 and 3.5 kyr BP yet decreasing from ~2 kyr BP until the present. Major climate parameters alone cannot explain the observed trend and thus it is not possible to rule out the hypothesis of early anthropogenic influences on fire activity. Over millennial timescales, temperature influences Arctic ice sheet extension and vegetation distribution at Northern Hemisphere high latitudes and may have altered the distance between NEEM and available fuel loads. During the last Glacial, the combination of dry and cold climate conditions, together with low boreal insolation and decreased atmospheric carbon dioxide levels may have also limited the production of available biomass. Diminished boreal forest extension and the southward

  19. Sequential extraction partitioning of trace and nutrient elements in ashes from biomass firing district heating plants

    Directory of Open Access Journals (Sweden)

    Šyc M.

    2013-04-01

    Full Text Available Four different ashes from three district heating plants firing biomass were studied with the respect to their potential application as soil fertilizers. Major and trace elements content and some important characteristics of the studied ashes are also presented. Five stage sequential extraction procedure was used for the determination of distribution and speciation of As, Ca, Cd, Cr, Cu, K, Mg, Na, Ni, Pb and Zn in studied ash samples.

  20. Sequential Extraction Partitioning of Trace and Nutrient Elements in Ashes from Biomass Firing District Heating Plants

    OpenAIRE

    Šyc M.; Tošnarová M.; Hrma J.; Pohořelý M.; Svoboda K.; Punčochář M.

    2012-01-01

    Four different ashes from three district heating plants firing biomass were studied with the respect to their potential application as soil fertilizers. Major and trace elements content and some important characteristics of the studied ashes are also presented. Five stage sequential extraction procedure was used for the determination of distribution and speciation of As, Ca, Cd, Cr, Cu, K, Mg, Na, Ni, Pb and Zn in studied ash samples.

  1. Deposition onto heat exchanger surfaces from the co-firing of coal and biomass

    OpenAIRE

    Legrave, Nigel A

    2011-01-01

    In the latter part of the 20th century, there has been a continuing global concern of the consumption of fossil fuels used in power production. There is further concern of the gaseous emissions that are created from this consumption and an awareness of climbing carbon dioxide (CO2) levels that are exhausted into the atmosphere. The concept of co-firing fossil fuel with varying levels of biomass species is not new but there is a requirement to explore its applications further...

  2. Formulation, Pretreatment, and Densification Options to Improve Biomass Specifications for Co-Firing High Percentages with Coal

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shankar Tumuluru; J Richard Hess; Richard D. Boardman; Shahab Sokhansanj; Christopher T. Wright; Tyler L. Westover

    2012-06-01

    There is a growing interest internationally to use more biomass for power generation, given the potential for significant environmental benefits and long-term fuel sustainability. However, the use of biomass alone for power generation is subject to serious challenges, such as feedstock supply reliability, quality, and stability, as well as comparative cost, except in situations in which biomass is locally sourced. In most countries, only a limited biomass supply infrastructure exists. Alternatively, co-firing biomass alongwith coal offers several advantages; these include reducing challenges related to biomass quality, buffering the system against insufficient feedstock quantity, and mitigating the costs of adapting existing coal power plants to feed biomass exclusively. There are some technical constraints, such as low heating values, low bulk density, and grindability or size-reduction challenges, as well as higher moisture, volatiles, and ash content, which limit the co-firing ratios in direct and indirect co-firing. To achieve successful co-firing of biomass with coal, biomass feedstock specifications must be established to direct pretreatment options in order to modify biomass materials into a format that is more compatible with coal co-firing. The impacts on particle transport systems, flame stability, pollutant formation, and boiler-tube fouling/corrosion must also be minimized by setting feedstock specifications, which may include developing new feedstock composition by formulation or blending. Some of the issues, like feeding, co-milling, and fouling, can be overcome by pretreatment methods including washing/leaching, steam explosion, hydrothermal carbonization, and torrefaction, and densification methods such as pelletizing and briquetting. Integrating formulation, pretreatment, and densification will help to overcome issues related to physical and chemical composition, storage, and logistics to successfully co-fire higher percentages of biomass ( > 40

  3. Logistics, Costs, and GHG Impacts of Utility-Scale Co-Firing with 20% Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Nichol, Corrie Ian [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-06-01

    This study analyzes the possibility that biopower in the U.S. is a cost-competitive option to significantly reduce greenhouse gas emissions. In 2009, net greenhouse gas (GHG) emitted in the United States was equivalent to 5,618 million metric tons CO2, up 5.6% from 1990 (EPA 2011). Coal-fired power generation accounted for 1,748 million metric tons of this total. Intuitively, life-cycle CO2 emissions in the power sector could be reduced by substituting renewable biomass for coal. If just 20% of the coal combusted in 2009 had been replaced with biomass, CO2 emissions would have been reduced by 350 million metric tons, or about 6% of net annual GHG emission. This would have required approximately 225 million tons of dry biomass. Such an ambitious fuel substitution would require development of a biomass feedstock production and supply system tantamount to coal. This material would need to meet stringent specifications to ensure reliable conveyance to boiler burners, efficient combustion, and no adverse impact on heat transfer surfaces and flue gas cleanup operations. Therefore, this report addresses the potential cost/benefit tradeoffs of co-firing 20% specification-qualified biomass (on an energy content basis) in large U.S. coal-fired power plants. The dependence and sensitivity of feedstock cost on source of material, location, supply distance, and demand pressure was established. Subsequently, the dependence of levelized cost of electricity (LCOE) on feedstock costs, power plant feed system retrofit, and impact on boiler performance was determined. Overall life-cycle assessment (LCA) of greenhouse gas emissions saving were next evaluated and compared to wind and solar energy to benchmark the leading alternatives for meeting renewable portfolio standards (or RPS).

  4. Assessment of fire emission inventories during the South American Biomass Burning Analysis (SAMBBA) experiment

    Science.gov (United States)

    Pereira, Gabriel; Siqueira, Ricardo; Rosário, Nilton E.; Longo, Karla L.; Freitas, Saulo R.; Cardozo, Francielle S.; Kaiser, Johannes W.; Wooster, Martin J.

    2016-06-01

    Fires associated with land use and land cover changes release large amounts of aerosols and trace gases into the atmosphere. Although several inventories of biomass burning emissions cover Brazil, there are still considerable uncertainties and differences among them. While most fire emission inventories utilize the parameters of burned area, vegetation fuel load, emission factors, and other parameters to estimate the biomass burned and its associated emissions, several more recent inventories apply an alternative method based on fire radiative power (FRP) observations to estimate the amount of biomass burned and the corresponding emissions of trace gases and aerosols. The Brazilian Biomass Burning Emission Model (3BEM) and the Fire Inventory from NCAR (FINN) are examples of the first, while the Brazilian Biomass Burning Emission Model with FRP assimilation (3BEM_FRP) and the Global Fire Assimilation System (GFAS) are examples of the latter. These four biomass burning emission inventories were used during the South American Biomass Burning Analysis (SAMBBA) field campaign. This paper analyzes and inter-compared them, focusing on eight regions in Brazil and the time period of 1 September-31 October 2012. Aerosol optical thickness (AOT550 nm) derived from measurements made by the Moderate Resolution Imaging Spectroradiometer (MODIS) operating on board the Terra and Aqua satellites is also applied to assess the inventories' consistency. The daily area-averaged pyrogenic carbon monoxide (CO) emission estimates exhibit significant linear correlations (r, p > 0.05 level, Student t test) between 3BEM and FINN and between 3BEM_ FRP and GFAS, with values of 0.86 and 0.85, respectively. These results indicate that emission estimates in this region derived via similar methods tend to agree with one other. However, they differ more from the estimates derived via the alternative approach. The evaluation of MODIS AOT550 nm indicates that model simulation driven by 3BEM and FINN

  5. A non-isothermal integrated model of coal-fired traveling grate boilers

    International Nuclear Information System (INIS)

    The aim of this study is to develop a mathematical model for coal combustion in traveling grate boilers. The model contains a 'bed-model' part and a 'furnace-model' part. Within the description of the 'bed-model', a non-isothermal particle model is proposed, in order to accommodate temperature gradients within combusting particles. The 'bed-model' is then coupled with the 'furnace-model' based on an integrated grid. To verify the model, an experimental fixed-bed furnace has been set up to simulate combustion in a real chain grate stoker. Concentrations of gas species at the bed surface have been measured. Predicted results are in reasonable agreement with experimental data. This has provided a basis for studying the effect of major parameters influencing boiler behavior, for optimizing combustion conditions. These factors have included the excess air ratio and particle diameter. The results show that there is an optimum excess air ratio required for optimized combustion and that smaller coal particle sizes (in the range of 0.02-0.04 m) enhance ignition and burnout properties of the fuel. It appears essential during operation to monitor and control excess air ratios and particle diameters carefully controlled.

  6. Technical, economic and environmental potential of co-firing of biomass in coal and natural gas fired power plants in the Netherlands

    International Nuclear Information System (INIS)

    In this paper the technical, economic, and environmental potential of co-firing of biomass in existing Dutch coal and natural gas fired power plants, and industrial combined-cycles (CC), is addressed. Main criteria that are considered are: the availability and contractibility of biomass for energy purposes; the (technical) operation of the conventional fossil fuel based processes may not be disturbed; the gaseous and liquid plant emissions have to comply to those applicable for power plants/CCs, the commercial applicability of the solid residues may not be negatively influenced; applicable additional biomass conversion technologies must be commercially available; the necessary additional investment costs must be acceptable from an economic point of view, and the co-firing option must result in a substantial CO2-emission reduction. The main result of the study described in the paper is the presentation of a clear and founded indication of the total co-firing potential of biomass in existing power plants and industrial CCs in the Netherlands. This potential is determined by considering both technical, economic, and environmental criteria. In spite of the fact that the co-firing potential for the specific Dutch situation is presented, the results of the criteria considered are more generally applicable, and therefore are also very interesting for potential co-firing initiatives outside of the Netherlands

  7. Effect of biomass on burnouts of Turkish lignites during co-firing

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H.; Yaman, S. [Istanbul Technical Univ., Chemical and Metallurgical Engineering Faculty, Chemical Engineering Dept., 34469 Maslak, Istanbul (Turkey)

    2009-09-15

    Co-firing of some low quality Turkish lignites with woody shells of sunflower seed was investigated via non-isothermal thermogravimetric analysis method. For this purpose, Yozgat-Sorgun, Erzurum-Askale, Tuncbilek, Gediz, and Afsin-Elbistan lignites were selected, and burnouts of these lignites were compared with those of their blends. Biomass was blended as much as 10 and 20 wt.% of the lignites, and heating was performed up to 900 C at a heating rate of 40 C/min under dry air flow of 40 mL/min. This study revealed that the same biomass species may have different influences on the burnout yields of the lignites. Burnouts of Erzurum-Askale lignite increased at any temperature with the increasing ratio of biomass in the blend, whereas burnout yields of other lignites decreased to some extent. Nevertheless, the blends of Turkish lignites with sunflower seed shell did not behave in very different way, and it can be concluded that they are compatible in terms of burnouts for co-combustion in a combustion system. Although the presence of biomass in the lignite blends caused to some decreases in the final burnouts, the carbon dioxide neutral nature of biomass should be taken into account, and co-combustion is preferable for waste-to-energy-management. (author)

  8. Cylindrical particle modelling in pulverized coal and biomass co-firing process

    International Nuclear Information System (INIS)

    Numerical analysis of co-firing pulverized coal and biomass in a vertical cylindrical laboratory furnace is explored. The ratio of coal and biomass in the fuel was 80:20 by mass for all cases. The mathematical model of combustion in the furnace was established by describing physical phenomena such as turbulent flow, heat and mass transfer, devolatilization and combustion. A 3D-model of combustion in a laboratory furnace was created using the CFD software FLUENT. The shape of the biomass particles was estimated as cylindrical and was accounted for in the calculation of particle trajectories via a custom-developed model. Experimental measurements were conducted on a 20 kW laboratory furnace with controllable wall temperature. The temperature varied in the range from 1233 K to 1823 K, depending on the case. Excess air for combustion was set at 10% or 20%, depending on the case. The developed model shows better agreement with the experimental data than the existing models, which estimate particles as spheres. Analysis of the results shows that the influence of the particle size increases with the size of the particle. Also, the geometry of the cylindrical particles strongly influences the beginning and the intensity of the devolatilization process and subsequently the combustion process. - Highlights: • Co-firing of pulverized biomass and coal is modelled using CFD Software Fluent. • Shape of biomass particles is taken into consideration in the model. • Geometry of particles influences the process of devolatilization and combustion. • Influence of the particle shape and size increases with the particle size

  9. Radiative Effects of Aerosols Generated from Biomass Burning, Dust Storms, and Forest Fires

    Science.gov (United States)

    Christopher Sundar A.; Vulcan, Donna V.; Welch, Ronald M.

    1996-01-01

    Atmospheric aerosol particles, both natural and anthropogenic, are important to the earth's radiative balance. They scatter the incoming solar radiation and modify the shortwave reflective properties of clouds by acting as Cloud Condensation Nuclei (CCN). Although it has been recognized that aerosols exert a net cooling influence on climate (Twomey et al. 1984), this effect has received much less attention than the radiative forcings due to clouds and greenhouse gases. The radiative forcing due to aerosols is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign (Houghton et al. 1990). Atmospheric aerosol particles generated from biomass burning, dust storms and forest fires are important regional climatic variables. A recent study by Penner et al. (1992) proposed that smoke particles from biomass burning may have a significant impact on the global radiation balance. They estimate that about 114 Tg of smoke is produced per year in the tropics through biomass burning. The direct and indirect effects of smoke aerosol due to biomass burning could add up globally to a cooling effect as large as 2 W/sq m. Ackerman and Chung (1992) used model calculations and the Earth Radiation Budget Experiment (ERBE) data to show that in comparison to clear days, the heavy dust loading over the Saudi Arabian peninsula can change the Top of the Atmosphere (TOA) clear sky shortwave and longwave radiant exitance by 40-90 W/sq m and 5-20 W/sq m, respectively. Large particle concentrations produced from these types of events often are found with optical thicknesses greater than one. These aerosol particles are transported across considerable distances from the source (Fraser et al. 1984). and they could perturb the radiative balance significantly. In this study, the regional radiative effects of aerosols produced from biomass burning, dust storms and forest fires are examined using the Advanced Very High Resolution Radiometer (AVHRR) Local Area

  10. Hybrid Combined Cycles with Biomass and Waste Fired Bottoming Cycle - a Literature Study

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Miroslav P.

    2002-02-01

    Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are very flexible and reliable. Their potential for high electric efficiency in condensing mode, high total efficiency in combined heat and power mode and unrivalled load flexibility is explored in this project. The present report is a literature study that concentrates on certain biomass utilization technologies, in particular the design and performance of hybrid combined cycle power units of various configurations, with gas turbines and internal combustion engines as topping cycles. An overview of published literature and general development trends on the relevant topic is presented. The study is extended to encompass a short overview of biomass utilization as an energy source (focusing on Sweden), history of combined cycles development with reference especially to combined cycles with supplementary firing and coal-fired hybrid combined cycles, repowering of old steam units into hybrid ones and combined cycles for internal combustion engines. The hybrid combined cycle concept for municipal solid waste

  11. Ozone Tendency in Biomass Burning Plumes: Influence of Biogenic and Anthropogenic Emissions Downwind of Forest Fires

    Science.gov (United States)

    Finch, D.; Palmer, P. I.

    2015-12-01

    Forest fires emit pollutants that can influence downwind surface concentrations of ozone, with potential implications for exceeding air quality regulations. The influence of emissions from biogenic and anthropogenic sources that are mixed into a biomass burning plume as it travels downwind is not well understood. Using the GEOS-Chem atmospheric chemistry transport model and a novel method to track the centre of biomass burning plumes, we identify the chemical reactions that determine ozone production and loss along the plume trajectory. Using a series of sensitivity runs, we quantify the role of biogenic and anthropogenic emissions on the importance of individual chemical reactions. We illustrate the method using data collected during the BORTAS aircraft campaign over eastern Canada during summer 2011. We focus on two contrasting plume trajectories originating from the same multi-day fire in Ontario. The first plume trajectory on 16th July 2011 travels eastward from the fire and eventually mixes with anthropogenic emissions travelling up the east coast of the United States before outflow over the North Atlantic. The second plume trajectory we follow is three days later and travels eastward with a strong northeast component away from large anthropogenic sources. Both trajectories are influenced by downwind biogenic emissions. We generate a chemical reaction narrative for each plume trajectory, allowing is to quantify how mixing pyrogenic, biogenic and anthropogenic emissions influences downwind ozone photochemistry.

  12. High temperature corrosion during biomass firing: improved understanding by depth resolved characterisation of corrosion products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming;

    2015-01-01

    The high temperature corrosion of an austenitic stainless steel (TP 347H FG), widely utilised as a superheater tube material in Danish power stations, was investigated to verify the corrosion mechanisms related to biomass firing. KCl coated samples were exposed isothermally to 560 degrees C...... changes within the near surface region (covering both the deposit and the steel surface). Such cross-section analysis was further complemented by plan view investigations (additionally involving X-ray diffraction) combined with removal of the corrosion products. Improved insights into the nature...... of the corrosion products as a function of distance from the deposit surface were revealed through this comprehensive characterisation. Corrosion attack during simulated straw-firing conditions was observed to occur through both active oxidation and sulphidation mechanisms....

  13. Suppression of dust explosions and ignition spots in biomass-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Wilen, C.; Rautalin, A.

    1995-12-31

    Dust explosion characteristics of forest residue dust both at normal pressure and at elevated initial pressure have been determined in previous studies. These indices give a good base for evaluating the usability of suppression systems to obtain a sufficient level of peritoneal safety in biomass fuel handling equipment. The objectives of this project were to evaluate the usability of suppression systems and to demonstrate dust explosion suppression at elevated initial pressure. Suppression tests at 1 - 20 bar pressure will be carried out in co-operation with CTDD of British Coal, Kiddy Fire Protection and Health and Safety Executive. The tests with coal and biomass dust are scheduled to be started in March 1996 in Great Britain. In the second task of the project, self-ignition properties of forest residue dust and straw dust have been measured in a flow-through system simulating slow drying of the fuel

  14. Suppression of dust explosions and ignition spots in biomass- fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Wilen, C.; Rautalin, A. [VTT Energy, Espoo (Finland)

    1997-12-01

    Dust explosion characteristics of forest residue dust both at normal pressure and at elevated initial pressure have been determined in previous studies. These indices give a good base for evaluating the usability of suppression systems to obtain a sufficient level of operational safety in biomass fuel handling equipment. The objectives of this project were to evaluate the usability of suppression systems and to demonstrate dust explosion suppression at elevated initial pressure. Suppression tests at 1 - 20 bar pressure will be carried out in co-operation with CTDD of British Coal, Kiddy Fire Protection and Health and Safety Executive. The tests with coal and biomass dust are scheduled to be started in March 1996 in Great Britain. In the second task of the project, self-ignition properties of forest residue dust and straw dust have been measured in a flow-through system simulating slow drying of the fuel

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-08-28

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

  16. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Bruce C. Folkedahl; Darren D. Schmidt; Greg F. Weber; Christopher J. Zygarlicke

    2001-10-01

    The Energy & Environmental Research Center (EERC) is conducting a project to examine the fundamental issues limiting the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC is attempting to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low volatile fuels with lower reactivities can experience damaging fouling when switched to higher volatile and more reactive lower-rank fuels, such as when cofiring biomass. Higher heat release rates at the grate can cause more clinkering or slagging at the grate because of higher temperatures. Combustion and loss of volatile matter can start too early for biomass fuels compared to the design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the stoker, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates and various chlorides, in combination with different flue gas temperatures because of changes in fuel heating value which can adversely affect ash deposition behavior. The goal of this project is to identify the primary ash mechanisms related to grate clinkering and heat exchange surface fouling associated with cofiring coal and biomass--specifically wood and agricultural residuals--in grate-fired systems, leading to future mitigation of these problems. The specific technical objectives of the project are: Modification of an existing EERC pilot-scale combustion system to simulate a grate-fired system; Verification testing of the simulator; Laboratory-scale testing and fuel characterization to determine ash

  17. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Bruce C. Folkedahl; Jay R. Gunderson; Darren D. Schmidt; Greg F. Weber; Christopher J. Zygarlicke

    2002-09-01

    The Energy & Environmental Research Center (EERC) has completed a project to examine fundamental issues that could limit the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC attempted to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low-volatile fuels with lower reactivities can experience problematic fouling when switched to higher-volatile and more reactive coal-biomass blends. Higher heat release rates at the grate can cause increased clinkering or slagging at the grate due to higher temperatures. Combustion and loss of volatile matter can start much earlier for biomass fuels compared to design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the stoker, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates, various chlorides, and phosphates. These species in combination with different flue gas temperatures, because of changes in fuel heating value, can adversely affect ash deposition behavior. The goal of this project was to identify the primary ash mechanisms related to grate clinkering and heat exchange surface fouling associated with cofiring coal and biomass--specifically wood and agricultural residuals--in grate-fired systems, leading to future mitigation of these problems. The specific technical objectives of the project were: (1) Modification of an existing pilot-scale combustion system to simulate a grate-fired system. (2) Verification testing of the simulator. (3) Laboratory-scale testing and fuel characterization to

  18. The influence of vegetation, fire spread and fire behaviour on biomass burning and trace gas emissions: results from a process-based model

    OpenAIRE

    K. Thonicke; A. Spessa; Prentice, I. C.; Harrison, S.P.; Dong, L.; C. Carmona-Moreno

    2010-01-01

    A process-based fire regime model (SPITFIRE) has been developed, coupled with ecosystem dynamics in the LPJ Dynamic Global Vegetation Model, and used to explore spatial and temporal patterns of fire regimes and the current impact of fire on the terrestrial carbon cycle and associated emissions of trace atmospheric constituents. The model estimates an average release of 2.24 Pg C yr−1 as CO2 from biomass burning during the 1980s and 1990s...

  19. Emission characteristics of volatile organic compounds from coal-, coal gangue-, and biomass-fired power plants in China

    Science.gov (United States)

    Yan, Yulong; Yang, Chao; Peng, Lin; Li, Rumei; Bai, Huiling

    2016-10-01

    Face the large electricity demand, thermal power generation still derives the main way of electricity supply in China, account for 78.19% of total electricity production in 2013. Three types of thermal power plants, including coal-fired power plant, coal gangue-fired power plant and biomass-fired power plant, were chosen to survey the source profile, chemical reactivity and emission factor of VOCs during the thermal power generation. The most abundant compounds generated during coal- and coal gangue-fired power generation were 1-Butene, Styrene, n-Hexane and Ethylene, while biomass-fired power generation were Propene, 1-Butenen, Ethyne and Ethylene. The ratios of B/T during thermal power generation in this study was 0.8-2.6, which could be consider as the characteristics of coal and biomass burning. The field tested VOCs emission factor from coal-, coal gangue- and biomass-fired power plant was determined to be 0.88, 0.38 and 3.49 g/GJ, or showed as 0.023, 0.005 and 0.057 g/kg, with the amount of VOCs emission was 44.07, 0.08, 0.45 Gg in 2013, respectively. The statistical results of previous emission inventory, which calculated the VOCs emission used previous emission factor, may overestimate the emission amount of VOCs from thermal power generation in China.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-15

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

  1. The influence of vegetation, fire spread and fire behaviour on biomass burning and trace gas emissions: results from a process-based model

    Directory of Open Access Journals (Sweden)

    K. Thonicke

    2010-01-01

    Full Text Available A process-based fire regime model (SPITFIRE has been developed, coupled with ecosystem dynamics in the LPJ Dynamic Global Vegetation Model, and used to explore spatial and temporal patterns of fire regimes and the current impact of fire on the terrestrial carbon cycle and associated emissions of trace atmospheric constituents. The model estimates an average release of 2.24 Pg C yr−1 as CO2 from biomass burning during the 1980s and 1990s. Comparison with observed active fire counts shows that the model reproduces where fire occurs and can mimic broad geographic patterns in the peak fire season, although the predicted peak is 1–2 months late in some regions. Modelled fire season length is generally overestimated by about one month, but shows a realistic pattern of differences among biomes. Comparisons with remotely sensed burnt-area products indicate that the model reproduces broad geographic patterns of annual fractional burnt area over most regions, including the boreal forest, although interannual variability in the boreal zone is underestimated. Overall SPITFIRE produces realistic simulations of spatial and temporal patterns of fire under modern conditions and of the current impact of fire on the terrestrial carbon cycle and associated emissions of trace greenhouse gases and aerosols.

  2. From biomass to biocarbon : trends and tradeoffs when CO-firing

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, H. [Alterna Energy Inc., Prince George, BC (Canada)

    2009-07-01

    This study examined current market dynamics for biomass-based fuels produced in British Columbia (BC) and consumed by utilities in Sweden. The aim of the study was to compare and develop the properties of 3 biofuels suitable for co-firing: (1) dry wood pellets; (2) torrefied wood pellets; and (3) biocarbon pellets. Biocarbon fuels are processed at higher temperatures to produce a higher energy density fuel per unit weight at a lower overall mass yield. The processing mass balances and physical properties of the pellets were investigated as well as the production and transportation costs of biofuels. Market value, profit, and maximum production costs of the pellets were examined. The study showed that the biofuel supply chain includes significant transportation costs relative to the cost of the raw biomass and biofuel conversion processes. It was concluded that higher energy density biocarbon pellets represent the most cost-effective biofuel option for co-firing with coal. 10 refs., 3 tabs., 4 figs.

  3. Detailed investigation of Cl-corrosion initiated by deposits formed in biomass-fired boilers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, Flemming J.; Lith, S. van

    2009-10-15

    The aim was to investigate deposit-induced Cl-corrosion under well-controlled laboratory conditions, simulating the conditions in biomass-fired boilers. This has been done by exposing pieces of superheater tubes, covered by synthetic salts, at temperatures and gas mixtures simulating biomass-fired conditions. The corroded specimens have been studied in detail using a Scanning Electron Microscope (SEM), in order to determine the corrosion rate, and to investigate the chemistry and morphology of the corrosive attack. The project has been divided into four activities: A1: Relationship between the Cl-concentration in the deposit, and the corrosion rate. A2: Influence of cation type (K+ and Na+) on the mobility of Cl in the deposit. A3: Influence of metal temperature on the corrosion rate. A4: Critical evaluation of the existing experience for minimizing corrosion in full-scale boilers firing totally or partly with biomass. (LN)

  4. Economic evaluation of externally fired gas turbine cycles for small-scale biomass cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2001-01-01

    In this conceptual study, externally fired gas turbine (EFGT) cycles in combination with a biomass-fueled, atmospheric circulating fluidized bed (CFB) furnace are investigated for small scale heat and power production ({approx} 8 MW fuel input). Three cycle configurations are considered: closed cycle, with nitrogen, helium, and a helium/carbon dioxide mixture as working fluids; open cycle operating in parallel to the CFB system; and open cycle with a series connection to the CFB system. Intercooling, postcooling, and recuperation are employed with the goal of maximizing efficiency. Aside from a thermodynamic performance analysis, the study includes an economic analysis of both the closed and open externally fired gas turbine configurations, and comparisons are made with existing and emerging alternatives for small-scale biomass cogeneration. Simulation results show that thermodynamic performance varies slightly between the different configurations and working fluids, with electrical efficiencies of 31-38% (LHV) and total efficiency of 85-106% (LHV). The economic evaluation shows that the turbomachinery and the CFB furnace dominate the total plant cost, with each contributing about 1/3 of the total installed equipment cost. The specific capital cost for installation in Sweden in 1998 currency is calculated as 26-31 kSEK/kW{sub e} which is equivalent to 3 200-3 900 USD/kW{sub e} or 2 700-3 300 EUR/kW{sub e} .The cost of electricity, COE, is estimated to 590-670 SEK/MWh{sub e} (equivalent to 73-84 USD/MWh{sub e} or 62-71 EUR/MWh{sub e}) for 4 000 full load hours per year in a cogeneration application. Comparing the economic results for the externally fired gas turbine cycles in a slightly larger scale (40-50 MW{sub f}) to the economics of conventional biomass fired steam turbine cycles shows that the cost of electricity for the two plant configurations are roughly the same with a COE of 300-350 SEK/MWh{sub e}. It is believed that the economic performance of the EFGT

  5. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Jay R. Gunderson; Bruce C. Folkedahl; Darren D. Schmidt; Greg F. Weber; Christopher J. Zygarlicke

    2002-05-01

    The Energy & Environmental Research Center (EERC) is conducting a project to examine the fundamental issues limiting the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC is attempting to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low-volatile fuels with lower reactivities can experience damaging fouling when switched to higher-volatile and more reactive lower-rank fuels, such as when cofiring biomass. Higher heat release rates at the grate can cause more clinkering or slagging at the grate because of higher temperatures. Combustion and loss of volatile matter can start too early with biomass fuels compared to design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the boiler, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates and various chlorides in combination with different flue gas temperatures because of changes in fuel heating value, which can adversely affect ash deposition behavior.

  6. Appraisal of biomass combustion biomarkers to track the paleo-occurrence of forest fires

    Science.gov (United States)

    Rivas-Ruiz, P.; Cao, M.; Rosell Mele, A.

    2015-12-01

    Wildfires influence many aspects of the Earth system, including ecosystem distribution, biodiversity, the carbon cycle, atmospheric chemistry and climate. The challenge is disentangling the various controls of fire, partly because of their diversity, and also because fire was impossible to observe and analyse as a global phenomenon until the satellite era. The study of ancient climates can be helpful to understand the natural drivers of wildfires. However, the reconstruction of wildfires is limited by the nature of the proxies available, chiefly charcoal, which only represents a portion of the carbon combustion continuum. In here we evaluate the application molecular combustion biomarkers. For this purpose we have compiled an extensive collection of soils and lacustrine sediments representative of the humid to arid environments, which encompass the wide range of climates and ecosystems within the Iberian peninsula. We have measured the abundance of a monosaccharide anhydride (MA) biomarker called levoglucosan (1,6-anhydro-β-D-glucopyranose) and polyaromatic hydrocarbons (PAHs), as well as general plant biomarkers such as n-alkanes. To discern between biogenic and/or anthropogenic combustion sources and the nature of fires we have investigated the use of levoglucosan, retene (PAH generated during combustion of conifer trees) and PAHs ratios such as phenantrane/anthracene and fluoranthene/pyrene. Charcoal (>150 microns) has also been measured in the lake samples to contribute in the assessment of local vs. regions fire signals. The final objective is to constrain the use of the molecular proxies as quantitative biomass combustion paleoproxies. The data obtained has been mapped and compared to the documented occurrence of wildfires in Spain over the last two decades, and mesoescale patterns of atmospheric circulation and particle transport. Results show that the occurrence of levoglucosan and PAHs is widespread in modern soils and sediments in Iberia. Chemical

  7. Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia during a high fire event

    OpenAIRE

    B. Aouizerats; G. R. van der Werf; Balasubramanian, R; R. Betha

    2015-01-01

    Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled a large fire-induced haze episode in 2006 stemming mostly from Indonesia using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). We focused on the evolution of the fire plume composition and its interaction with the urbanized area of the city state of Singapore, and on comparisons of modeled and measured aeroso...

  8. Monetization of External Costs Using Lifecycle Analysis—A Comparative Case Study of Coal-Fired and Biomass Power Plants in Northeast China

    OpenAIRE

    Lingling Wang; Tsunemi Watanabe; Zhiwei Xu

    2015-01-01

    In this study, the structures of external costs are built in line with coal-fired and biomass power plant life cycle activities in Northeast China. The external cost of coal-fired and biomass power plants was compared, using the lifecycle approach. In addition, the external costs of a biomass power plant are calculated for each stage for comparison with those of a coal-fired power plant. The results highlight that the external costs of a coal-fired plant are 0.072 US $/kWh, which are much hig...

  9. Effects of plant post-fire persistence traits on soil microbial biomass and activity in Mediterranean shrublands

    Directory of Open Access Journals (Sweden)

    R. López-Poma

    2013-05-01

    Full Text Available The strong relationships between plant and soil microbial communities suggest that post-fire vegetation may be a critical driver of the post-fire recovery of the structure and functioning of the soil microbial community. In this study, we conducted an experimental burning and evaluated the effect of the post-fire persistence traits of the vegetation (resprouter and seeder on the medium-term (3 years after fire post-fire response of the soil microbial activity in Mediterranean shrublands. The experiment was carried out in a Mediterranean shrubland (Eastern Spain, where four main types of microsites were selected: Bare-soil inter-patch (BS; Resprouter patch (R, Seeder patch (S, and Mixed patch (R+S. For each microsite, we analyzed soil basal respiration, water-soluble carbon, microbial biomass carbon, total organic carbon, and dehydrogenase activity at 0-5 cm soil depth. We also assessed plant cover dynamics. Our results suggest that, in general, fire impacts on soil microbial activity are not long-lasting, with most assessed soil variables being similar between burned and unburned areas three years after the fire. However, while the unburned microsites showed a trend in microbial biomass and activity from lower values in bare soils to higher values in R+S patches, these differences disappeared in the burned area, due to both a slight increase in microbial activity and biomass in bare soils, and the opposite response for soils under R+S patches. Our results highlight the role of the plant persistence trait in the microbial post-fire response of Mediterranean soils.

  10. Pre-oxidation and its effect on reducing high-temperature corrosion of superheater tubes during biomass firing

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Kvisgaard, M.; Montgomery, Melanie;

    2016-01-01

    Superheater tubes in biomass-fired power plants experience high corrosion rates due to condensation of corrosive alkali chloride-rich deposits. To explore the possibility of reducing the corrosion attack by the formation of an initial protective oxide layer, the corrosion resistance of pre-oxidis...

  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. Monetization of External Costs Using Lifecycle Analysis—A Comparative Case Study of Coal-Fired and Biomass Power Plants in Northeast China

    Directory of Open Access Journals (Sweden)

    Lingling Wang

    2015-02-01

    Full Text Available In this study, the structures of external costs are built in line with coal-fired and biomass power plant life cycle activities in Northeast China. The external cost of coal-fired and biomass power plants was compared, using the lifecycle approach. In addition, the external costs of a biomass power plant are calculated for each stage for comparison with those of a coal-fired power plant. The results highlight that the external costs of a coal-fired plant are 0.072 US $/kWh, which are much higher than that of a biomass power plant, 0.00012 US$/kWh. The external cost of coal-fired power generation is as much as 90% of the current price of electricity generated by coal, while the external cost of a biomass power plant is 1/1000 of the current price of electricity generated by biomass. In addition, for a biomass power plant, the external cost associated with SO2, NOX, and PM2.5 are particularly lower than those of a coal-fired power plant. The prospect of establishing precise estimations for external cost mechanisms and sustainable energy policies is discussed to show a possible direction for future energy schemes in China. The paper has significant value for supporting the biomass power industry and taxing or regulating coal-fired power industry to optimize the energy structure in China.

  13. Retrieval of fire radiative power and biomass combustion using the Korean geostationary meteorological satellite

    Science.gov (United States)

    Kim, D. S.; Lee, Y. W.

    2013-10-01

    Global warming induced by greenhouse gases is increasing wildfire frequencies and scale. Since wildfire again releases greenhouse gases(GHGs) into the air, the vicious cycle is repeated. Satellite remote sensing is a useful tool for detecting wildfire. However, estimating the GHGs emission from wildfire has not been challenged yet. Wildfires are estimated to be responsible for, on average, around 30% of global total CO emissions, 10% of methane emissions, 38% of tropospheric ozone, and over 86% of black carbon. So we need to quantify the emitted gases by biomass combustions, which can be measured by the FRP (fire radiative power) derived from the spectral characteristics of satellite sensors. This paper described the algorithm for retrieval of FRP using COMS(Communication, Ocean and Meteorological Satellite), the Korean geostationary meteorological satellite. The FRP of wildfire is retrieved by single waveband methods suitable to COMS channels. The retrieval of FRP is dependent on the emissivity of each bandwidth. So, we used MODIS NDVI through a spatio-temporal calibration for the emissivity calculations. We made sure that the FRP in wildfire pixel is much higher than its spatially and temporally neighboring pixels. For future work, we should quantify the relationships between FRP and the biomass combustion according to fuel types.

  14. Investigation of Biomass Combustion Rate of Fire Radiative Energy Using Multiple-Satellite-observed Active Fires and Landsat TM Burn Severities across the Continental United States

    Science.gov (United States)

    Li, F.; Zhang, X.; Kondragunta, S.

    2015-12-01

    Biomass burning is a major source of atmospheric aerosol and greenhouse gases that substantially influence climate and regional air quality. However, the accuracy of biomass burning emissions estimated using traditional method is limited by large uncertainties in burned area and fuel loading. Alternatively, fire radiative energy (FRE) has recently been demonstrated to be linearly related to biomass combustion, which potentially improves the estimation of biomass burning emissions. The FRE-based combustion rate is 0.368-0.453 kg/MJ according to field controlled experiments while it varies from 1.37-4.5 kg/MJ derived from satellite-based bottom-up and top-down aerosol optical thickness estimates. Here we investigate the FRE combustion rate in over 1000 burn scars from 2011 to 2012 across the Continental United States (CONUS). Specifically, FRE was calculated by combining the high spatial observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the high temporal observations from the Geostationary Operational Environmental Satellite (GOES). Biomass consumption in burn scars was modeled using Landsat TM 30m burn severities, 30m fuel loading from Fuel Characteristic Classification System, and combustion completeness compiled from recent literatures. The combustion rate was then investigated by correlating FRE to biomass consumption across CONUS and Bailey's ecoregions. Our results show that the combustion rate can be extracted from the linear relationship between biomass consumption and FRE. The combustion rate is 0.415±10% kg/MJ across CONUS, which is similar to the rate derived from field experiments. However, it varies from 0.18-1.9 kg/MJ among ecoregions. This implies that a single combustion rate could produce large uncertainty in the estimation of biomass consumption at large scales. We suggest that ecoregion specified combustion rates should help to improve the accuracy of quantifying biomass burning emissions regionally and globally.

  15. TECHNOLOGY OF SMOKE PREVENTION AND DUST CONTROL FOR HORIZONTAL GRATE-FIRED BOILERS%卧式层状燃煤锅炉炉内消烟除尘技术

    Institute of Scientific and Technical Information of China (English)

    王擎; 孙东红; 孙佰仲; 闫跃升; 孙键

    2003-01-01

    In China, a number of horizontal grate-fired boilers have been used in industry and black soot and fly ash are emitted out of the furnace. A smoke prevention and dust control device suited for horizontal grate-fired boilers is invented so as to solve these two problems. The technical feature of the device is presented and aerodynamic field in the furnace is simulated. It shows many advantages,such as simple structure, easy arrangement, effective inhibition of soot formation and realizing dust-removal in furnace.

  16. Study of a 30 MW bubbling fluidized bed combustor based on co-firing biomass and coal

    Indian Academy of Sciences (India)

    Hemant Kumar; S K Mohapatra; Ravi Inder Singh

    2015-06-01

    Today’s power generation sources are largely dependent on fossil fuels due to which the future sustainable development has become a challenge. A significant amount of the pollutant emissions such as carbon dioxide, carbon monoxide and nitrogen oxide from the power sector is related to the use of fossil fuels for power generation. As the demand for electricity is growing rapidly, emissions of carbon dioxide and other pollutants from this sector can be expected to increase unless other alternatives are made available. Among the energy sources that can substitute fossil fuels, biomass fuels appear as one of the options with a high worldwide potential. In the Punjab region of India, Fluidized-bed combustion technology is being used for converting biomass into thermal energy and power generation in various small scale units. The investigation of biomass-based plant through experimental activities and numerical simulation is the scope of this study. The investigations were done at Captive Power Plant (CPP), Ambuja Cement Limited, a project of Holcim, District Ropar, India. During experimental investigations, the study of bed temperatures and steam temperatures at different zones has been done for coal fired and biomass fired combustors with 30% share. No clear effects of co-firing on boiler performance are observed. However, the operational behavior of the boiler in terms of bed temperature and stack emissions shows a different trend. During simulation, the contours of temperature have been obtained for both the boilers and the trends are found in agreement with real process.

  17. Feasibility analysis of co-fired combined-cycles using biomass-derived gas and natural gas

    International Nuclear Information System (INIS)

    This paper reports the feasibility analysis of co-fired combined cycles (biomass-derived gas + natural gas) based on the gasification of sugarcane residues (bagasse and trash). Performance results are based on simulation of co-fired combined cycles. Feasibility analysis is based on estimates of the capital costs and O and M costs for such cycles, taking into account current and middle term costs of BIG-CC technology (both considering scaling and learning effects). A deep reduction of the investments regarding the gasification island and auxiliaries is a key point to make BIG-CC competitive in the electricity market, and the required learning can be reached with co-fired BIG-CC systems. Besides alleviation of technical problems related to gas turbine operation with biomass-derived gas, co-fired BIG-CC units can operate with relative flexibility regarding the fuel mix. The construction of 10-15 short- to medium-size gasification islands would be enough to induce important cost reductions due to learning effects. As long as the investment on the gasification island is reduced, and depending on the price ratio of natural gas and biomass, pure BIG-CC plants could achieve a reasonable level of feasibility regarding other options of electricity production. In the short run there is no advantage for co-fired combined cycles regarding the costs of reduction of carbon dioxide emissions, but in the middle run both co-fired and pure BIG-CC power plants can be a better option than capture and storage of CO2

  18. Effects of climate change on fire and spruce budworm disturbance regimes and consequences on forest biomass production in eastern Canada

    International Nuclear Information System (INIS)

    The dynamics of spruce budworm (SBW) outbreaks and wildfires are expected to change as climatic change progresses. The effects of an altered, combined interaction between SBW and fire may be of greater importance than the individual effect of either on forest biomass production. The objectives of this study are to define current fire and SBW regimes in eastern Canada and relate the characteristics of each regime based upon climate model outputs for 2050 and 2100. The study also attempts to evaluate the impact of predicted changes in SBW and fire disturbance regimes on forest dynamics. The methodology used in the study included data from the Canadian Large Fire Database and historical records of SBW outbreaks. Spatial and environmental variables were presented along with climate models. The analysis was conducted using constrained ordination techniques, and canonical correspondence and redundancy analysis. Projected disturbance regimes were presented for both fire and SBW. The effects of the regimes on biomass productivity were also examined, using a Landscape Disturbance Simulator (LAD). It was concluded that this model will help evaluate the consequences of changes imposed by climatic change on both disturbances individually, as well as their interaction. 10 refs., 1 tab., 2 figs

  19. Closed-loop biomass co-firing in a laboratory reactor and in a full-scale boiler.

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Bryan M. (University of California, Davis, CA); Williams, Robert B. (University of California, Davis, CA); Turn, Scott Q. (Hawaii Natural Energy Institute.); Jakeway, Lee A. (Hawaiian Commercial & Sugar Company); Blevins, Linda Gail

    2004-05-01

    Co-firing tests were conducted in a pilot-scale reactor at Sandia National Laboratories and in a boiler at the Hawaiian Commercial & Sugar factory at Puunene, Hawaii. Combustion tests were performed in the Sandia Multi-Fuel Combustor using Australian coal, whole fiber cane including tops and leaves processed at three different levels (milled only, milled and leached, and milled followed by leaching and subsequent milling), and fiber cane stripped of its tops and leaves and heavily processed through subsequent milling, leaching, and milling cycles. Testing was performed for pure fuels and for biomass co-firing with the coal at levels of 30% and 70% by mass. The laboratory tests revealed the following information: (1) The biomass fuels convert their native nitrogen into NO more efficiently than coal because of higher volatile content and more reactive nitrogen complexes. (2) Adding coal to whole fiber cane to reduce its tendency to form deposits should not adversely affect NO emissions. ( 3 ) Stripped cane does not offer a NO advantage over whole cane when co-fired with coal. During the field test, Sandia measured 0 2 , C02, CO, SO2, and NO concentrations in the stack and gas velocities near the superheater. Gas concentrations and velocities fluctuated more during biomass co-firing than during coal combustion. The mean 0 2 concentration was lower and the mean C02 concentration was higher during biomass co-firing than during coal combustion. When normalized to a constant exhaust 0 2 concentration, mean CO concentration was higher and mean NO concentration was lower for biomass co-firing than for coal. The SO2 concentration tracked the use of Bunker C fuel oil. When normalized by the amount of boiler energy input, the amounts of NO and SO2 formed were lower during biomass co-firing than during coal combustion. The difference between NOx trends in the lab and in the field are most likely a result of less effective heat and mass transfer in the boiler. Particles were

  20. Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Hedman, Henry; Nordgren, Daniel; Bostroem, Dan; Oehman, Marcus; Padban, Nader

    2011-01-15

    The use of straw in pulverised fuel-fired boiler is great technical challenge, especially when it comes to dealing with problems from slagging and fouling. Introduction of straw in the fuel mix of Swedish boilers will most likely be done by co-firing of woody biomass with straw, and this can provide a means to reduce the (well-documented) problems with fouling and slagging from straw. The project will focus on the faith of alkali metals (K and Na) as well as studies on the slagging and fouling propensity in pulverised fuel-fired boilers when straw is co-fired with woody biomass. A total of 5 different fuel mixtures has been fired in a 150 kW pilot-scale pulverised fuel-fired burner: (i) straw 100 %, (ii) straw/bark 50/50 %, (iii) straw/bark 75/25 % (iv) straw/wood 75/25 % (v) straw/wood 50/50 % (wt-%). The adding of woody biomass to straw has in all of the above-mentioned cases had some positive effect. In general, in all of the ash deposits, an increase in the concentration of Calcium (Ca) has been observed as well as a decrease in the concentrations of Potassium (K) and Silicon (Si). These general trends should be considered as a positive when combustion of straw is considered. Out of all ash deposits collected in the furnace, the characteristics of the bottom ash displayed the largest (positive) change and visual inspections and chemical analysis of the bottom ash showed that the ash had become more porous and contained more Calcium as more woody biomass was introduced in the fuel mix. The deposit build-up rate on the air cooled probes was reduced when more woody biomass was co-fired with straw. The reduction was highest in the trial where 50% woody biomass was used and the most apparent changes in composition could be seen in Calcium (increase) and Potassium (decrease). Danish experiences from introducing straw in pulverised fuel-fired boiler indicate that extra soot-blowers should be considered at the furnace walls and in connection to screen-tubes (if any

  1. Prediciton of the remaining service life of superheater and reheater tubes in coal-biomass fired power plants

    OpenAIRE

    Asgaryan, Mohammad

    2013-01-01

    As a result of concern about the effects of CO2 emssions on the global warming, there is increasing pressure to reduce such emissions from power generation systems. The use of biomass co-firing with coal in conventional pulverised fuel power plants has provided the most immediate route to introduce a class of fuel that is regarded as both sustainable and carbon neutral as it produces less net CO2 emissions. In the future it is anticipated that increased levels of biomass will be required to u...

  2. Modeling of biomass smoke injection into the lower stratosphere by a large forest fire (Part II: sensitivity studies

    Directory of Open Access Journals (Sweden)

    G. Luderer

    2006-01-01

    Full Text Available The Chisholm forest fire that burned in Alberta, Canada, in May 2001 resulted in injection of substantial amounts of smoke into the lower stratosphere. We used the cloud-resolving plume model ATHAM (Active Tracer High resolution Atmospheric Model to investigate the importance of different contributing factors to the severe intensification of the convection induced by the Chisholm fire and the subsequent injection of biomass smoke into the lower stratosphere. The simulations show strong sensitivity of the pyro-convection to background meteorology. This explains the observed coincidence of the convective blow-up of the fire plume and the passage of a synoptic cold front. Furthermore, we performed model sensitivity studies to the rate of release of sensible heat and water vapor from the fire. The release of sensible heat by the fire plays a dominant role for the dynamic development of the pyro-cumulonimbus cloud (pyroCb and the height to which smoke is transported. The convection is very sensitive to the heat flux from the fire. The emissions of water vapor play a less significant role for the injection height but enhance the amount of smoke transported beyond the tropopause level. The aerosol burden in the plume has a strong impact on the microphysical structure of the resulting convective cloud. The dynamic evolution of the pyroCb, however, is only weakly sensitive to the abundance of cloud condensation nuclei (CCN from the fire. In contrast to previous findings by other studies of convective clouds, we found that fire CCN have a negative effect on the convection dynamics because they give rise to a delay in the freezing of cloud droplets. Even in a simulation without fire CCN, there is no precipitation formation within the updraft region of the pyroCb. Enhancement of convection by aerosols as reported from studies of other cases of convection is therefore not found in our study.

  3. Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia during a high fire event

    Science.gov (United States)

    Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

    2015-01-01

    Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled a large fire-induced haze episode in 2006 stemming mostly from Indonesia using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). We focused on the evolution of the fire plume composition and its interaction with the urbanized area of the city state of Singapore, and on comparisons of modeled and measured aerosol and carbon monoxide (CO) concentrations. Two simulations were run with WRF-Chem using the complex volatility basis set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic and biomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent data sets for comparison including airborne measurements of particulate matter (PM) with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and aerosol optical depth (AOD) column observations from four satellite-based sensors. We found reasonable agreement between the model runs and both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while the secondary organic aerosol (SOA) concentration

  4. Large-scale analysis of GHG (greenhouse gas) reduction by means of biomass co-firing at country-scale: Application to the Spanish case

    International Nuclear Information System (INIS)

    The knowledge of the potentially achievable reduction of greenhouse gas (GHG) emissions by biomass co-firing is a powerful tool in supporting decision makers when it comes to undertaking energy planning. The main goal of this work was to develop a methodology by which significant biomass co-firing potentials and subsequent reduced GHG emissions, could be obtained at large territories. This methodology has been applied to Spain. It has been found that agricultural and forestry residual biomass feedstocks, available within 100 km of coal-fired power plants (CPP), currently total up to 75.8 PJth/yr. If energy crop feedstocks are included, this quantity increases up to 91.1 PJth/yr. However, the utilisation of biomass in CPPs is constrained by technical limitations. Taking into account these restrictions, biomass could be co-fired to generate up to 7.7% of electricity produced in CPPs (42.1 PJth/yr of biomass). A life cycle assessment has been performed to all the processes involved. The results indicate that up to 87 tCO2eq can be reduced by utilising 1 TJth of biomass replacing coal. The combination of these figures points out that biomass co-firing could contribute to mitigating 3.4 MtCO2eq in Spain annually. This value equates to almost 1% of its total GHG emissions.

  5. Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska

    Science.gov (United States)

    Mack, M.C.; Treseder, K.K.; Manies, K.L.; Harden, J.W.; Schuur, E.A.G.; Vogel, J.G.; Randerson, J.T.; Chapin, F. S., III

    2008-01-01

    Plant biomass accumulation and productivity are important determinants of ecosystem carbon (C) balance during post-fire succession. In boreal black spruce (Picea mariana) forests near Delta Junction, Alaska, we quantified aboveground plant biomass and net primary productivity (ANPP) for 4 years after a 1999 wildfire in a well-drained (dry) site, and also across a dry and a moderately well-drained (mesic) chronosequence of sites that varied in time since fire (2 to ???116 years). Four years after fire, total biomass at the 1999 burn site had increased exponentially to 160 ?? 21 g m-2 (mean ?? 1SE) and vascular ANPP had recovered to 138 ?? 32 g m-2 y -1, which was not different than that of a nearby unburned stand (160 ?? 48 g m-2 y-1) that had similar pre-fire stand structure and understory composition. Production in the young site was dominated by re-sprouting graminoids, whereas production in the unburned site was dominated by black spruce. On the dry and mesic chronosequences, total biomass pools, including overstory and understory vascular and non-vascular plants, and lichens, increased logarithmically (dry) or linearly (mesic) with increasing site age, reaching a maximum of 2469 ?? 180 (dry) and 4008 ?? 233 g m-2 (mesic) in mature stands. Biomass differences were primarily due to higher tree density in the mesic sites because mass per tree was similar between sites. ANPP of vascular and non-vascular plants increased linearly over time in the mesic chronosequence to 335 ?? 68 g m-2 y -1 in the mature site, but in the dry chronosequence it peaked at 410 ?? 43 g m-2 y-1 in a 15-year-old stand dominated by deciduous trees and shrubs. Key factors regulating biomass accumulation and production in these ecosystems appear to be the abundance and composition of re-sprouting species early in succession, the abundance of deciduous trees and shrubs in intermediate aged stands, and the density of black spruce across all stand ages. A better understanding of the controls

  6. Alkali deposits found in biomass boilers: The behavior of inorganic material in biomass-fired power boilers -- Field and laboratory experiences. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, L.L. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Miles, T.R.; Miles, T.R. Jr. [Miles (Thomas R.), Portland, OR (United States); Jenkins, B.M. [California Univ., Davis, CA (United States); Dayton, D.C.; Milne, T.A. [National Renewable Energy Lab., Golden, CO (United States); Bryers, R.W. [Foster Wheeler Development Corp., Livingston, NJ (United States); Oden, L.L. [Bureau of Mines, Albany, OR (United States). Albany Research Center

    1996-03-01

    This report documents the major findings of the Alkali Deposits Investigation, a collaborative effort to understand the causes of unmanageable ash deposits in biomass-fired electric power boilers. Volume 1 of this report provide an overview of the project, with selected highlights. This volume provides more detail and discussion of the data and implications. This document includes six sections. The first, the introduction, provides the motivation, context, and focus for the investigation. The remaining sections discuss fuel properties, bench-scale combustion tests, a framework for considering ash deposition processes, pilot-scale tests of biomass fuels, and field tests in commercially operating biomass power generation stations. Detailed chemical analyses of eleven biomass fuels representing a broad cross-section of commercially available fuels reveal their properties that relate to ash deposition tendencies. The fuels fall into three broad categories: (1) straws and grasses (herbaceous materials); (2) pits, shells, hulls and other agricultural byproducts of a generally ligneous nature; and (3) woods and waste fuels of commercial interest. This report presents a systematic and reasonably detailed analysis of fuel property, operating condition, and boiler design issues that dictate ash deposit formation and property development. The span of investigations from bench-top experiments to commercial operation and observations including both practical illustrations and theoretical background provide a self-consistent and reasonably robust basis to understand the qualitative nature of ash deposit formation in biomass boilers. While there remain many quantitative details to be pursued, this project encapsulates essentially all of the conceptual aspects of the issue. It provides a basis for understanding and potentially resolving the technical and environmental issues associated with ash deposition during biomass combustion. 81 refs., 124 figs., 76 tabs.

  7. Burnout model of a grate-firing waste incinerator for complete simulation of the combustion space; Abbrandmodell einer Muellrostfeuerung fuer eine vollstaendige Feuerraumsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Kruell, F.; Kremer, H.; Wirtz, S. [Bochum Univ. (Germany). Lehrstuhl Energieanlagentechnik

    1998-09-01

    In the past few decades, grate firing has become an established technology for incineration of residual waste and other materials of the domestic waste type. Process control is difficult because of the heterogeneous nature of the waste which is also subject to seasonal and regional variations. In addition, the waste composition may change significantly as a result of recycling as required by new laws. (orig.) [Deutsch] In den letzten Jahrzehnten hat sich die Rostfeuerung fuer die thermische Entsorgung von Restmuell und hausmuellaehnlichem Gewerbemuell bewaehrt. Die Prozessfuehrung bzw. die Feuerfuehrung solcher Anlagen wird insbesondere durch die starke Heterogenitaet des Muells erschwert, der zusaetzlich jahreszeitlichen und regionalen Schwankungen unterliegt. Zudem kann es in der Zusammensetzung der einzelnen Abfallarten durch die Entnahme von Wertstoffen infolge der Umsetzung von gesetzlichen Vorschriften und Gesetzen - wie Abfallgesetz und Kreislaufwirtschaftsgesetz - zu signifikanten Verschiebungen kommen. (orig.)

  8. Experimental Investigation into the Combustion Characteristics on the Co-firing of Biomass with Coal as a Function of Particle Size and Blending Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Lkhagvadorj, Sh; Kim, Sang In; Lim, Ho; Kim, Seung Mo; Jeon, Chung Hwan [Pusan National Univ., Busan (Korea, Republic of); Lee, Byoung Hwa [Doosan Heavy Industries and Construction, Ltd., Changwon (Korea, Republic of)

    2016-01-15

    Co-firing of biomass with coal is a promising combustion technology in a coal-fired power plant. However, it still requires verifications to apply co-firing in an actual boiler. In this study, data from the Thermogravimetric analyzer(TGA) and Drop tube furnace(DTF) were used to obtain the combustion characteristics of biomass when co-firing with coal. The combustion characteristics were verified using experimental results including reactivity from the TGA and Unburned carbon(UBC) data from the DTF. The experiment also analyzed with the variation of the biomass blending ratio and biomass particle size. It was determined that increasing the biomass blending ratio resulted in incomplete chemical reactions due to insufficient oxygen levels because of the rapid initial combustion characteristics of the biomass. Thus, the optimum blending condition of the biomass based on the results of this study was found to be 5 while oxygen enrichment reduced the increase of UBC that occurred during combustion of blended biomass and coal.

  9. Application of an empirical model in CFD simulations to predict the local high temperature corrosion potential in biomass fired boilers

    International Nuclear Information System (INIS)

    To gain reliable data for the development of an empirical model for the prediction of the local high temperature corrosion potential in biomass fired boilers, online corrosion probe measurements have been carried out. The measurements have been performed in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Within the test runs the flue gas temperature at the corrosion probe has been varied between 625 °C and 880 °C, while the steel temperature has been varied between 450 °C and 550 °C to simulate typical current and future live steam temperatures of biomass fired steam boilers. To investigate the dependence on the flue gas velocity, variations from 2 m·s−1 to 8 m·s−1 have been considered. The empirical model developed fits the measured data sufficiently well. Therefore, the model has been applied within a Computational Fluid Dynamics (CFD) simulation of flue gas flow and heat transfer to estimate the local corrosion potential of a wood chips fired 38 MW steam boiler. Additionally to the actual state analysis two further simulations have been carried out to investigate the influence of enhanced steam temperatures and a change of the flow direction of the final superheater tube bundle from parallel to counter-flow on the local corrosion potential. - Highlights: • Online corrosion probe measurements in a fixed bed/drop tube reactor. • Development of an empirical corrosion model. • Application of the model in a CFD simulation of flow and heat transfer. • Variation of boundary conditions and their effects on the corrosion potential

  10. Improving Large-scale Biomass Burning Carbon Consumption and Emissions Estimates in the Former Soviet Union based on Fire Weather

    Science.gov (United States)

    Westberg, D. J.; Soja, A. J.; Tchebakova, N.; Parfenova, E. I.; Kukavskaya, E.; de Groot, B.; McRae, D.; Conard, S. G.; Stackhouse, P. W., Jr.

    2012-12-01

    Estimating the amount of biomass burned during fire events is challenging, particularly in remote and diverse regions, like those of the Former Soviet Union (FSU). Historically, we have typically assumed 25 tons of carbon per hectare (tC/ha) is emitted, however depending on the ecosystem and severity, biomass burning emissions can range from 2 to 75 tC/ha. Ecosystems in the FSU span from the tundra through the taiga to the forest-steppe, steppe and desserts and include the extensive West Siberian lowlands, permafrost-lain forests and agricultural lands. Excluding this landscape disparity results in inaccurate emissions estimates and incorrect assumptions in the transport of these emissions. In this work, we present emissions based on a hybrid ecosystem map and explicit estimates of fuel that consider the depth of burning based on the Canadian Forest Fire Weather Index System. Specifically, the ecosystem map is a fusion of satellite-based data, a detailed ecosystem map and Alexeyev and Birdsey carbon storage data, which is used to build carbon databases that include the forest overstory and understory, litter, peatlands and soil organic material for the FSU. We provide a range of potential carbon consumption estimates for low- to high-severity fires across the FSU that can be used with fire weather indices to more accurately estimate fire emissions. These data can be incorporated at ecoregion and administrative territory scales and are optimized for use in large-scale Chemical Transport Models. Additionally, paired with future climate scenarios and ecoregion cover, these carbon consumption data can be used to estimate potential emissions.

  11. Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P.; Laatikainen-Luntama, J. [VTT Energy, Espoo (Finland). Energy Production Technologies] [and others

    1997-10-01

    The conventional fluidized-bed combustion has become commercially available also to relatively small scale (5 MWe), but this technology has rather low power-to-heat ratio and consequently it`s potential is limited to applications where district or process heat is the main product. Thus, there seems to be a real need to develop more efficient methods for small-scale power production from biomass. Gasification diesel power plant is one alternative for the small-scale power production, which has clearly higher power-to-heat ratio than can be reached in conventional steam cycles. The main technical problem in this process is the gas cleaning from condensable tars. In addition to the diesel-power plants, there are several other interesting applications for atmospheric-pressure clean gas technology. One alternative for cost-effective biomass utilization is co-firing of biomass derived product gas in existing pulverized coal fired boilers (or other types of boilers and furnaces). The aim of the project is to develop dry gas cleaning methods for gasification-diesel power plants and for other atmospheric-pressure applications of biomass and waste gasification. The technical objectives of the project are as follows: To develop and test catalytic gas cleaning methods for engine. To study the removal of problematic ash species of (CFE) gasification with regard to co-combustion of the product gas in PC boilers. To evaluate the technical and economical feasibility of different small-scale power plant concepts based on fixed-bed updraft and circulating fluidized- bed gasification of biomass and waste. (orig.)

  12. Modelling and prediction of air pollutant transport during the 2014 biomass burning and forest fires in peninsular Southeast Asia.

    Science.gov (United States)

    Duc, Hiep Nguyen; Bang, Ho Quoc; Quang, Ngo Xuan

    2016-02-01

    During the dry season, from November to April, agricultural biomass burning and forest fires especially from March to late April in mainland Southeast Asian countries of Myanmar, Thailand, Laos and Vietnam frequently cause severe particulate pollution not only in the local areas but also across the whole region and beyond due to the prevailing meteorological conditions. Recently, the BASE-ASIA (Biomass-burning Aerosols in South East Asia: Smoke Impact Assessment) and 7-SEAS (7-South-East Asian Studies) studies have provided detailed analysis and important understandings of the transport of pollutants, in particular, the aerosols and their characteristics across the region due to biomass burning in Southeast Asia (SEA). Following these studies, in this paper, we study the transport of particulate air pollution across the peninsular region of SEA and beyond during the March 2014 burning period using meteorological modelling approach and available ground-based and satellite measurements to ascertain the extent of the aerosol pollution and transport in the region of this particular event. The results show that the air pollutants from SEA biomass burning in March 2014 were transported at high altitude to southern China, Hong Kong, Taiwan and beyond as has been highlighted in the BASE-ASIA and 7-SEAS studies. There are strong evidences that the biomass burning in SEA especially in mid-March 2014 has not only caused widespread high particle pollution in Thailand (especially the northern region where most of the fires occurred) but also impacted on the air quality in Hong Kong as measured at the ground-based stations and in LulinC (Taiwan) where a remote background monitoring station is located. PMID:26797812

  13. Transboundary Transport of Biomass Burning Emissions in Southeast Asia and Contribution to Local Air Quality During the 2006 Fire Event

    Science.gov (United States)

    Aouizerats, B.; van der Werf, G.; Balasubramanian, R.; Betha, R.

    2014-12-01

    Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled the largest fire-induced haze episode in the past decade (2006) that originated in Indonesia using WRF-Chem. Our study addressed 3 research questions: (1) Can the WRF-Chem model reproduce observations of both aerosol and CO concentrations in this complex region? (2) What is the evolution in the chemical composition of the aerosol fire plume during its atmospheric transport? and (3) What is the relative contribution of these fires to air quality in the urbanized area of the city-state of Singapore? To test model performance, we used three independent datasets for comparison (PM10 in Singapore, CO measurements in Sumatra, and AOD column observations from 4 satellite-based sensors). We found reasonable agreement of the model runs with ground-based measurements of both CO and PM10. However, the comparison with AOD was less favorable and indicated the model underestimated AOD. In the past, modeling studies using only AOD as a constraint have often boosted fire emissions to get a better agreement with observations. In our case, this approach would seriously deteriorate the difference with ground-based observations. Finally, our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to the influence of biomass and peat burning in Sumatra, with an increased contribution during high burning periods. The composition of this biomass burning plume was largely dominated by primary organic carbon. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 (WHO threshold). During 17 days this deterioration was due to Indonesian fires, based on the difference between the simulations with and without fires. Local air pollution in combination with recirculation of air masses was probably the main

  14. The evolution of biomass-burning aerosol size distributions due to coagulation: dependence on fire and meteorological details and parameterization

    Science.gov (United States)

    Sakamoto, Kimiko M.; Laing, James R.; Stevens, Robin G.; Jaffe, Daniel A.; Pierce, Jeffrey R.

    2016-06-01

    Biomass-burning aerosols have a significant effect on global and regional aerosol climate forcings. To model the magnitude of these effects accurately requires knowledge of the size distribution of the emitted and evolving aerosol particles. Current biomass-burning inventories do not include size distributions, and global and regional models generally assume a fixed size distribution from all biomass-burning emissions. However, biomass-burning size distributions evolve in the plume due to coagulation and net organic aerosol (OA) evaporation or formation, and the plume processes occur on spacial scales smaller than global/regional-model grid boxes. The extent of this size-distribution evolution is dependent on a variety of factors relating to the emission source and atmospheric conditions. Therefore, accurately accounting for biomass-burning aerosol size in global models requires an effective aerosol size distribution that accounts for this sub-grid evolution and can be derived from available emission-inventory and meteorological parameters. In this paper, we perform a detailed investigation of the effects of coagulation on the aerosol size distribution in biomass-burning plumes. We compare the effect of coagulation to that of OA evaporation and formation. We develop coagulation-only parameterizations for effective biomass-burning size distributions using the SAM-TOMAS large-eddy simulation plume model. For the most-sophisticated parameterization, we use the Gaussian Emulation Machine for Sensitivity Analysis (GEM-SA) to build a parameterization of the aged size distribution based on the SAM-TOMAS output and seven inputs: emission median dry diameter, emission distribution modal width, mass emissions flux, fire area, mean boundary-layer wind speed, plume mixing depth, and time/distance since emission. This parameterization was tested against an independent set of SAM-TOMAS simulations and yields R2 values of 0.83 and 0.89 for Dpm and modal width, respectively. The

  15. Fires

    Science.gov (United States)

    Whether a fire happens in your home or in the wild, it can be very dangerous. Fire spreads quickly. There is no time to gather ... a phone call. In just two minutes, a fire can become life-threatening. In five minutes, a ...

  16. Fire in the Vegetation and Peatlands of Borneo, 1997-2007: Patterns, Drivers and Emissions from Biomass Burning

    Science.gov (United States)

    Spessa, Allan; Weber, Ulrich; Langner, Andreas; Siegert, Florian; Heil, Angelika

    2010-05-01

    correlations are noticeably much weaker or absent in Sarawak and Sabah, and central Borneo, where little or no deforestation was observed. Emissions from biomass burning reflect fire activity, and that fires in the carbon-rich peats of southern Kalimantan dominate the emissions profile during the El Nino years of 1997-98, 2002, 2004 and 2006. Previous work in southern Amazon forests demonstrates that recurrent fires promote a change from tree-dominated to grass-dominated ecosystems which, in turn, promotes even more fires. We show that recurrent fire and deforestation are also linked as part of a similar positive feedback process in Kalimantan. Our results support the detailed field work undertaken in 1997-98 in East Kalimantan, and reinforce these findings across time and space. Emissions from fires in Kalimantan peatlands represent a serious perturbation in terms of forcing from trace gases and aerosols on regional and global climate. Several global and regional climate modelling studies have reported that equatorial SE Asia, including Borneo, will experience reduced rainfall in future decades. At the same time, demands for establishing pulp paper and palm oil plantations to replace native rainforests, especially on peatlands where tenure conflicts among land owners tend to be minimal, is forecast to increase. These joint scenarios imply even more fires and emissions in future. It is critical therefore that present efforts to mitigate emissions through reduced deforestation programs in the region works, otherwise the consequences will be disastrous.

  17. Assessment of the most adequate pre-treatments and woody biomass sources intended for direct co-firing in the U.S.

    Directory of Open Access Journals (Sweden)

    Daniel Saloni

    2012-11-01

    Full Text Available There is increasing interest in replacing coal with woody biomass in co-firing plants for electrical power. A variety of pre-treatments can be used to make biomass more suitable for co-firing. This research presents a model that evaluates the delivered costs of various pre-treated biomass sources, electricity production costs, and constraints, and calculates a least cost mix. Results of the scenario presented indicate that wood chips are the most economical co-firing option for delivering biomass to direct-fired boilers. Apart from potential feeding and processing issues, the wood-chips options of forest residues present the lowest cost of electricity production for small-scale co-firing applications. From the options that will ensure minimum processing issues in the co-firing cycle, wood pellets from southern yellow pine represent the most economical choice. Based on coal displacement from the facility, torrefied wood pellets from southern yellow pine is a preferred option as compared to other choices evaluated. An alternative to torrefied wood pellets from southern yellow pine is dark torrefied Eucalyptus benthamii, providing similar electricity production costs while reducing coal utilization.

  18. Investigations on torrefied biomass for co-combustion in pulverised coal-fired furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Alobaid, Falah; Busch, Jan-Peter; Stroehle, Jochen; Epple, Bernd [Technische Univ. Darmstadt (Germany). Inst. for Energy Systems and Technology

    2012-07-01

    The torrefaction process is a thermal treatment of raw biomass during the absence of oxygen at a temperature range between 200 to 300 C and at a residence time of 15 to 90 minutes under atmospheric pressure. Here, the released water and low calorific volatile components reduce the mass by approximately 30 % while the energy content of torrefied biomass decreases by about 10 %. Compared to raw biomass, torrefied biomass is easier to grind and has a high energy density similar to coal. The Institute for Energy Systems and Technology (EST) at the Technische Universitaet Darmstadt is currently researching the torrefaction process of biomass. The proposed model will be validated towards the measurements in the frame of a CFD simulation program. (orig.)

  19. Observations of biomass burning smoke from Russian wild fire episodes in Finland 2010

    Science.gov (United States)

    Leino, K.; Nieminen, T.; Väänänen, R.; Petäjä, T.; Järvi, L.; Keronen, P.; Laurila, T.; Virkkula, A.; Pohja, T.; Aalto, P. P.; Kulmala, M.

    2013-05-01

    Forest and peat bog fires occur almost every summer in several parts of Russian boreal forests due to long rainless and heat periods at summertime. Particulate matter and different gases (CO, CO2, NOx, O3, SO2) in air can be transported thousands of kilometers away from the fire areas. Increased concentrations of the different parameters, like carbon monoxide and aerosol particles were observed on certain days in Southern Finland and even Finnish Lapland during Russian wild fire episodes in summer 2010. During these days the wind direction was from East or Southeast to Finland.

  20. CFD modeling of small biomass-fired boilers, second stage; CFD-modellering av mindre biobraenslepannor, etapp 2

    Energy Technology Data Exchange (ETDEWEB)

    Loennermark, A. [Swedish National Testing and Research Inst., Boraas (Sweden); Leckner, B. [Chalmers Univ. of Techn., Goeteborg (Sweden). Dept. of Energy Technology

    2001-11-01

    The purpose of the project is to study how the design of the gas combustion chamber in a small boiler for biomass affects the emissions and how computer simulations can be used to decrease harmful emissions. The aim of the first part of the project was to investigate how phenomena and processes, important for the combustion, depend on various parameters. Within the frame of that part the temperature distribution, the flow pattern and the mixing processes have been studied. In the second part the combustion and the different reactions have been studied. A number of well-equipped combustion experiments in a small biomass-fired boiler have also been conducted to obtain better information about the boundary conditions. The results have been used to verify the simulations. The gas combustion chamber of a modern boiler using down draught firing has been simulated by using two Computational Fluid Dynamics codes, SOFIE and FLUENT. The results from the simulations show that with literature values for the reaction parameters, the reaction rates are controlled by mixing. This means that the reactions are fast and all the CO and the hydrocarbons were consumed. By varying the activation energy, it is possible to reach data that are more comparable with experimental data. The effects of the bowl in the gas combustion chamber on the combustion and mixing are discussed. The effects of the temperature and the radiation are also presented.

  1. Availability of Biomass Residues for Co-Firing in Peninsular Malaysia: Implications for Cost and GHG Emissions in the Electricity Sector

    Directory of Open Access Journals (Sweden)

    W. Michael Griffin

    2014-02-01

    Full Text Available Fossil fuels comprise 93% of Malaysia’s electricity generation and account for 36% of the country’s 2010 Greenhouse Gas (GHG emissions. The government has targeted the installation of 330 MW of biomass electricity generation capacity by 2015 to avoid 1.3 Mt of CO2 emissions annually and offset some emissions due to increased coal use. One biomass option is to co-fire with coal, which can result in reduced GHG emissions, coal use, and costs of electricity. A linear optimization cost model was developed using seven types of biomass residues for Peninsular Malaysia. Results suggest that about 12 Mt/year of residues are available annually, of which oil-palm residues contribute 77%, and rice and logging residues comprise 17%. While minimizing the cost of biomass and biomass residue transport, co-firing at four existing coal plants in Peninsular Malaysia could meet the 330 MW biomass electricity target and reduce costs by about $24 million per year compared to coal use alone and reduces GHG emissions by 1.9 Mt of CO2. Maximizing emissions reduction for biomass co-firing results in 17 Mt of CO2 reductions at a cost of $23/t of CO2 reduced.

  2. Predicting the Effects of Woody Encroachment on Mammal Communities, Grazing Biomass and Fire Frequency in African Savannas.

    Science.gov (United States)

    Smit, Izak P J; Prins, Herbert H T

    2015-01-01

    With grasslands and savannas covering 20% of the world's land surface, accounting for 30-35% of worldwide Net Primary Productivity and supporting hundreds of millions of people, predicting changes in tree/grass systems is priority. Inappropriate land management and rising atmospheric CO2 levels result in increased woody cover in savannas. Although woody encroachment occurs world-wide, Africa's tourism and livestock grazing industries may be particularly vulnerable. Forecasts of responses of African wildlife and available grazing biomass to increases in woody cover are thus urgently needed. These predictions are hard to make due to non-linear responses and poorly understood feedback mechanisms between woody cover and other ecological responders, problems further amplified by the lack of long-term and large-scale datasets. We propose that a space-for-time analysis along an existing woody cover gradient overcomes some of these forecasting problems. Here we show, using an existing woody cover gradient (0-65%) across the Kruger National Park, South Africa, that increased woody cover is associated with (i) changed herbivore assemblage composition, (ii) reduced grass biomass, and (iii) reduced fire frequency. Furthermore, although increased woody cover is associated with reduced livestock production, we found indigenous herbivore biomass (excluding elephants) remains unchanged between 20-65% woody cover. This is due to a significant reorganization in the herbivore assemblage composition, mostly as a result of meso-grazers being substituted by browsers at increasing woody cover. Our results suggest that woody encroachment will have cascading consequences for Africa's grazing systems, fire regimes and iconic wildlife. These effects will pose challenges and require adaptation of livelihoods and industries dependent on conditions currently prevailing.

  3. Predicting the Effects of Woody Encroachment on Mammal Communities, Grazing Biomass and Fire Frequency in African Savannas.

    Directory of Open Access Journals (Sweden)

    Izak P J Smit

    Full Text Available With grasslands and savannas covering 20% of the world's land surface, accounting for 30-35% of worldwide Net Primary Productivity and supporting hundreds of millions of people, predicting changes in tree/grass systems is priority. Inappropriate land management and rising atmospheric CO2 levels result in increased woody cover in savannas. Although woody encroachment occurs world-wide, Africa's tourism and livestock grazing industries may be particularly vulnerable. Forecasts of responses of African wildlife and available grazing biomass to increases in woody cover are thus urgently needed. These predictions are hard to make due to non-linear responses and poorly understood feedback mechanisms between woody cover and other ecological responders, problems further amplified by the lack of long-term and large-scale datasets. We propose that a space-for-time analysis along an existing woody cover gradient overcomes some of these forecasting problems. Here we show, using an existing woody cover gradient (0-65% across the Kruger National Park, South Africa, that increased woody cover is associated with (i changed herbivore assemblage composition, (ii reduced grass biomass, and (iii reduced fire frequency. Furthermore, although increased woody cover is associated with reduced livestock production, we found indigenous herbivore biomass (excluding elephants remains unchanged between 20-65% woody cover. This is due to a significant reorganization in the herbivore assemblage composition, mostly as a result of meso-grazers being substituted by browsers at increasing woody cover. Our results suggest that woody encroachment will have cascading consequences for Africa's grazing systems, fire regimes and iconic wildlife. These effects will pose challenges and require adaptation of livelihoods and industries dependent on conditions currently prevailing.

  4. Large-scale biodiesel production using flue gas from coal-fired power plants with Nannochloropsis microalgal biomass in open raceway ponds.

    Science.gov (United States)

    Zhu, Baohua; Sun, Faqiang; Yang, Miao; Lu, Lin; Yang, Guanpin; Pan, Kehou

    2014-12-01

    The potential use of microalgal biomass as a biofuel source has raised broad interest. Highly effective and economically feasible biomass generating techniques are essential to realize such potential. Flue gas from coal-fired power plants may serve as an inexpensive carbon source for microalgal culture, and it may also facilitate improvement of the environment once the gas is fixed in biomass. In this study, three strains of the genus Nannochloropsis (4-38, KA2 and 75B1) survived this type of culture and bloomed using flue gas from coal-fired power plants in 8000-L open raceway ponds. Lower temperatures and solar irradiation reduced the biomass yield and lipid productivities of these strains. Strain 4-38 performed better than the other two as it contained higher amounts of triacylglycerols and fatty acids, which are used for biodiesel production. Further optimization of the application of flue gas to microalgal culture should be undertaken.

  5. Sustainable sources of biomass for bioremediation of heavy metals in waste water derived from coal-fired power generation.

    Directory of Open Access Journals (Sweden)

    Richard J Saunders

    Full Text Available Biosorption of heavy metals using dried algal biomass has been extensively described but rarely implemented. We contend this is because available algal biomass is a valuable product with a ready market. Therefore, we considered an alternative and practical approach to algal bioremediation in which algae were cultured directly in the waste water stream. We cultured three species of algae with and without nutrient addition in water that was contaminated with heavy metals from an Ash Dam associated with coal-fired power generation and tested metal uptake and bioremediation potential. All species achieved high concentrations of heavy metals (to 8% dry mass. Two key elements, V and As, reached concentrations in the biomass of 1543 mg.kg(-1 DW and 137 mg.kg(-1 DW. Growth rates were reduced by more than half in neat Ash Dam water than when nutrients were supplied in excess. Growth rate and bioconcentration were positively correlated for most elements, but some elements (e.g. Cd, Zn were concentrated more when growth rates were lower, indicating the potential to tailor bioremediation depending on the pollutant. The cosmopolitan nature of the macroalgae studied, and their ability to grow and concentrate a suite of heavy metals from industrial wastes, highlights a clear benefit in the practical application of waste water bioremediation.

  6. Superheater corrosion in biomass-fired power plants: Investigation of Welds

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Carlsen, B; Biede, O;

    2002-01-01

    condense on superheater components. This gives rise to specific corrosion problems not previously encountered in coal-fired power plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. A test superheater was built into the straw-fired...... Masnedø combined heat and power (CHP) plant to investigate corrosion at temperatures higher than that of the actual plant. The highest steam temperature investigated was 570°C. Various alloys of 12-22% chromium content were welded into this test loop. Their corrosion rates were similar and increased...

  7. Probe Measurements of Ash Deposit Formation Rate and Shedding in a Biomass Suspension-Fired boiler

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    The aim of this study was to investigate ash deposit formation rate, heat uptake reduction and deposit removal by using advanced online ash deposition and sootblowing probes in a 350 MWth suspension-fired boiler, utilizing wood and straw pellets as fuel. The influence of fuel type (straw share....... The video recordings of all deposit probe experiments revealed that deposit shedding was primarily through debonding from the surface of the tubes in the superheater region. Chemical analysis of fly ashes indicated that during suspension-firing of straw and wood, the fly ashes were rich in Si, K, Ca and Cl...

  8. Optimisation of the outburning of ash in grate-fired boilers by means of IR-sensors. Demonstration of the applicability of the method; Optimering av askutbraenning vid rosteldade anlaeggningar med hjaelp av IR-sensorer. Demonstration av teknikens tillaempbarhet

    Energy Technology Data Exchange (ETDEWEB)

    Rudling, L. [TPS Termiska Processer AB, Nykoeping (Sweden)

    1999-11-01

    The objective of the project was to demonstrate if it is possible by means of a continuous measurement of the fuel-bed temperature along the grate with infrared pyrometers, to optimise the burnout of the ash on the grate by controlling the air-supply. The tests were carried out at a refuse-fuel grate-fired boiler at Hoegdalen, Stockholm. To monitor the temperature of the fuel-bed, 5 pyrometers were installed. The signals from the pyrometers were connected to a PLC, by which the air dampers for the air-supply of the grate could be controlled. To avoiding 'long fire' with bad burnout the distribution of the air was changed when an increase in temperature was detected in the final burnout zone of the grate Results: * By using a slim encapsulation of the infrared sensor, it was possible to obtain such small dimensions of the pyrometer that it could be installed in the fin-wall between the water tubes., * By choosing a suitable installation point for the pyrometer and a good control of the flow and quality of the rinsing air it was possible to obtain a high availability for the pyrometers., * When an increase of the bed-temperature in the last roller zone, from the 500-600 deg C to the 600-700 deg C was detected, the amount of unburned residue in the ash increased from 2-5 % to 5-10 %. By monitoring the temperature of the fuel-bed in the burnout zone of the grate by means of IR-pyrometry, it was possible to indicate operation conditions with a poor burnout. Tests carried out with automatic control of the air supply to the burnout zone based on measured bed temperatures by IR-pyrometry were carried out. The distribution of the burnout air was performed in a manner that when an increase in bed temperature in the burnout zone was detected the amount of air to the last zone was increased and vice versa. During these tests the amount of unburned matter in the ash removed from the grate was 3.5 %, which shall be compared to 4.3 % which was obtained with manual

  9. Occupational exposure at a contemplated Belarussian power plant fired with contaminated biomass

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Fogh, C.L.; Roed, Jørn

    1999-01-01

    To meet the current demand in Belarus for remediation of the vast forest areas that were contaminated by the Chernobyl accident and at the same time establish a much needed energy production, applying contaminated forest biomass as fuel in special power plants is being considered. This paper...

  10. Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming;

    2013-01-01

    Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe th...

  11. Laboratory Investigations of Ni-Al Coatings Exposed to Conditions Simulating Biomass Firing

    DEFF Research Database (Denmark)

    Wu, Duoli; Okoro, Sunday Chukwudi; Dahl, Kristian Vinter;

    2016-01-01

    Fireside corrosion is a key problem when using biomass fuels in power plants. A possible solution is to apply corrosion resistant coatings. The present paper studies the corrosion and interdiffusion behaviour of a Ni-Al diffusion coating on austenitic stainless steel (TP347H). Ni-Al coatings were...

  12. Co-firing biomass and coal-progress in CFD modelling capabilities

    DEFF Research Database (Denmark)

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

    2005-01-01

    This paper discusses the development of user defined FLUENT™ sub models to improve the modelling capabilities in the area of large biomass particle motion and conversion. Focus is put on a model that includes the influence from particle size and shape on the reactivity by resolving intra-particle...

  13. Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

    Science.gov (United States)

    Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

    2013-01-01

    The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection.

  14. Deposition and High-Temperature Corrosion in Biomass-Fired Boilers

    DEFF Research Database (Denmark)

    Michelsen, Hanne Philbert

    This thesis describes the fate of potassium, chlorine, and sulfur in regard to deposition and corrosion problems in straw-fired boilers. Full-scale deposition studies at Rudkøbing CHP, Kyndby Power Station and Masnedø CHP revealed that straw may form massive deposits in the convective pass...... has only been detected in insignificant amounts in mature deposits in straw-fired boilers formed over months of operation.The corrosion of superheater tubes is closely connected to the material which are deposited on the surface and deposits containing potassium chloride can cause severe high......-temperature corrosion at elevated metal temperatures. Lab-scale corrosion experiments, where metal test elements were covered with synthetic potassium salts and real deposits and exposed to a simulated flue gas containing HCl(g) and SO2(g), provided information about the corrosion rate and corrosion mechanisms...

  15. Injection in the lower stratosphere of biomass fire emissions followed by long-range transport: a MOZAIC case study

    Directory of Open Access Journals (Sweden)

    J.-P. Cammas

    2009-08-01

    Full Text Available This paper analyses a stratospheric injection by deep convection of biomass fire emissions over North America (Alaska, Yukon and Northwest Territories on 24 June 2004 and its long-range transport over the eastern coast of the United States and the eastern Atlantic. The case study is based on airborne MOZAIC observations of ozone, carbon monoxide, nitrogen oxides and water vapour during the crossing of the southernmost tip of an upper level trough over the Eastern Atlantic on 30 June and on a vertical profile over Washington DC on 30 June, and on lidar observations of aerosol backscattering at Madison (University of Wisconsin on 28 June. Attribution of the observed CO plumes to the boreal fires is achieved by backward simulations with a Lagrangian particle dispersion model (FLEXPART. A simulation with the Meso-NH model for the source region shows that a boundary layer tracer, mimicking the boreal forest fire smoke, is lofted into the lowermost stratosphere (2–5 pvu layer during the diurnal convective cycle at isentropic levels (above 335 K corresponding to those of the downstream MOZAIC observations. It is shown that the order of magnitude of the time needed by the parameterized convective detrainment flux to fill the volume of a model mesh (20 km horizontal, 500 m vertical above the tropopause with pure boundary layer air would be about 7.5 h, i.e. a time period compatible with the convective diurnal cycle. Over the area of interest, the maximum instantaneous detrainment fluxes deposited about 15 to 20% of the initial boundary layer tracer concentration at 335 K. According to the 275-ppbv carbon monoxide maximum mixing ratio observed by MOZAIC over Eastern Atlantic, such detrainment fluxes would be associated with a 1.4–1.8 ppmv carbon monoxide mixing ratio in the boundary layer over the source region.

  16. Development and evaluation of a biomass-fired micro-scale CHP with organic rankine cycle

    OpenAIRE

    Shao, Yingjuan

    2011-01-01

    Combined Heat and Power Generation (CHP) or cogeneration has been considered worldwide as the major alternative to traditional energy systems in terms of signi ticant energy saving and environmental conservation. A renewable energy resource-fuelled CHP would deliver even more environmental benefits than a fossil tuel-driven CHP. Biomass is one of the renewable energy resources that plays an important role to the world primary energy supplies and can be used to fuel CHP systems. Many medium- a...

  17. Biomass direct-fired power generation system in China: An integrated energy, GHG emissions, and economic evaluation for Salix

    International Nuclear Information System (INIS)

    To gain a better understanding of the options of biomass power generation in China, this study presented an integrated energy, environmental, and economic evaluation for Salix in China, and a typical Salix direct-fired power generation system (SDPGS) in Inner Mongolia was selected for case study. A tiered hybrid life cycle assessment (LCA) model was developed to calculate the “planting-to-wire” (PTW) energy consumption, greenhouse gas (GHG) emissions, and economic cost and profit of the SDPGS, including feedstock cultivation, power plant construction and operation, and on-grid price with/without government subsidies. The results show that the PTW energy consumption and GHG emissions of Salix are 0.8 MJ/kWh and 114 g CO2-eq/kWh, respectively, indicating an energy payback time (EPBT) of 3.2 years. The SDPGS is not economically feasible without government subsidies. The PTW costs are dominated by feedstock cultivation. The energy saving and GHG mitigation benefits are still robust, even when the power plant runs at only 60% design capacity. For future development of biomass power in China, scientific planning is necessary to guarantee a sufficient feedstock supply. In addition, technology progress, mature industrial chains, and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward. -- Highlights: •A hybrid LCA model was used to evaluate overall performance of the SDPGS. •On-site processes dominate the “planting-to-wire” footprints. •The energy saving and GHG mitigation benefits of the SDPGS are robust. •The economic profit of the SDPGS is feeble without government subsidies. •Generating efficiency promotion has a comprehensive positive effect on the system

  18. ALTENER - Biomass event in Finland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The publication contains the lectures held in the Biomass event in Finland. The event was divided into two sessions: Fuel production and handling, and Co-combustion and gasification sessions. Both sessions consisted of lectures and the business forum during which the companies involved in the research presented themselves and their research and their equipment. The fuel production and handling session consisted of following lectures and business presentations: AFB-NETT - business opportunities for European biomass industry; Wood waste in Europe; Wood fuel production technologies in EU- countries; new drying method for wood waste; Pellet - the best package for biofuel - a view from the Swedish pelletmarket; First biomass plant in Portugal with forest residue fuel; and the business forum of presentations: Swedish experiences of willow growing; Biomass handling technology; Chipset 536 C Harvester; KIC International. The Co-combustion and gasification session consisted of following lectures and presentations: Gasification technology - overview; Overview of co-combustion technology in Europe; Modern biomass combustion technology; Wood waste, peat and sludge combustion in Enso Kemi mills and UPM-Kymmene Rauma paper mill; Enhanced CFB combustion of wood chips, wood waste and straw in Vaexjoe in Sweden and Grenaa CHP plant in Denmark; Co-combustion of wood waste; Biomass gasification projects in India and Finland; Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti (FI); Biomass gasification for energy production, Noord Holland plant in Netherlands and Arbre Energy (UK); Gasification of biomass in fixed bed gasifiers, Wet cleaning and condensing heat recovery of flue gases; Combustion of wet biomass by underfeed grate boiler; Research on biomass and waste for energy; Engineering and consulting on energy (saving) projects; and Research and development on combustion of solid fuels

  19. Short term effects of prescribed fire on soil microbial biomass of black pine forests

    OpenAIRE

    Akbaş, Musa; Sağlam, Bülent; Tüfekçioğlu, Aydın; Dinç, Musa

    2014-01-01

    In this study, we were examined of changes microbial carbon (MBC) and microbial Nitrogen (MBN) after one month controlled fire. The study area consist of sloping and flat areas, high and low intensity of burnt areas and control areas (unburned) including (flat low intensity: FLI, flat high intensity: FHI, smooth low intensity: SLI, smooth high intensity: SHI and 0-5 cm and 5-10 cm depth soil). In terms of microbial carbon on the upper soil in the flat high intensity and upper and lower soil i...

  20. Fuel characterization requirements for cofiring biomass in coal-fired boilers

    International Nuclear Information System (INIS)

    The cofiring of biofuels with coal in existing boilers, or the cofiring of biofuels in combined cycle combustion turbine (CCCT) systems presents significant potential benefits to utilities, including reductions in SO2 and NOx emissions as a function of reducing the mass flow of sulfur and nitrogen to the boiler, reducing CO2 emissions from the combustion of fossil fuels; potentially reducing fuel costs both by the availability of wood residues and by the fact that biofuels are exempt from the proposed BTU tax; and providing support to industrial customers from the forest products industry. At the same time, cofiring requires careful attention to the characterization of the wood and coal, both singly and in combination. This paper reviews characterization requirements associated with cofiring biofuels and fossil fuels in boilers and CCCT installations with particular attention not only to such concerns as sulfur, nitrogen, moisture, and Btu content, but also to such issues as total ash content, base/acid ratio of the wood ash and the coal ash, alkali metal content in the wood ash and wood fuel (including converted fuels such as low Btu gas or pyrolytic oil), slagging and fouling indices, ash fusion temperature, and trace metal contents in the wood and coal. The importance of each parameter is reviewed, along with potential consequences of a failure to adequately characterize these parameters. The consequences of these parameters are reviewed with attention to firing biofuels with coal in pulverized coal (PC) and cyclone boilers, and firing biofuels with natural gas in CCCT installations

  1. Biomass-modulated fire dynamics during the last glacial-interglacial transition at the central pyrenees (Spain)

    OpenAIRE

    Gil-Romera, Graciela; González-Sampériz, Penélope; Lasheras Álvarez, Laura; Sevilla-Callejo, Miguel; Moreno Caballud, Ana; Valero-Garcés, Blas L.; López-Merino, Lourdes; José S Carrión; Pérez Sanz, Ana; Aranbarri, J.; Garcia-Prieto, E

    2014-01-01

    Understanding long-term fire ecology is essential for current day interpretation of ecosystem fire responses. However palaeoecology of fire is still poorly understood, especially at high-altitude mountain environments, despite the fact that these are fire-sensitive ecosystems and their resilience might be affected by changing fire regimes. We reconstruct wildfire occurrence since the Lateglacial (14.7. cal. ka BP) to the Mid-Holocene (6. cal. ka BP) and investigate the climate-fuel-fire relat...

  2. Detection of Biomass Fires and Tracking of Plumes in Southeast Brazil with S-Band Radars and TITAN Software

    Science.gov (United States)

    Held, Gerhard; Saraiva, Ernandes A.; Gomes, Ana M.; Lopes, Fabio J. S.; Ramires, Thiago

    2013-04-01

    The S-band radars of the Meteorological Research Institute (IPMet) in Bauru and Presidente Prudente are situated within major sugar cane producing regions in the State of São Paulo, where the sugar cane is harvested from April until November, generally by burning sectors of the plantations prior to manual harvesting, resulting in large quantities of aerosols being emitted into the atmosphere, not only negatively affecting local towns, but also regions much further away. In the absence of rain during the dry winter season, the actual fires and subsequent plumes can be observed by IPMet's S-band Doppler radars within their 240 km quantitative ranges, deploying a special scanning cycle which was configured to provide a better vertical resolution up to the anticipated detectable top of the plumes (10 elevations from 10,0° down to 0,3°; resolution of 250 m in range and 1° in azimuth; 7,5 min per volume scan). During August 2010, a one-month multi-disciplinary pilot study was executed with two-fold objectives in two separate regions of the Bauru radar range: to verify the onset of the actual fire and quantify the combustion process and to characterize the effects of those emissions on the atmosphere. The TITAN (Thunderstorm Identification, Tracking, Analysis and Nowcasting) Software was deployed to determine the intensity of the initial fire (based on radar reflectivity in dBZ), and subsequently the horizontal and vertical dimensions of the smoke plume and the velocity of dispersion. The thresholds used for tracking the smoke envelopes were 10 dBZ with a minimum volume of 2 km3, but the position and extent of already diluted plumes could be identified up to 100-150 km range at -6 dBZ. Samples of the biomass material were collected to characterize and quantify the fuel mass before and after burning, which could be related to the fire intensity and subsequent aerosol density of the smoke plume (experimental site ca 50 km east of Bauru). At another remote site (Ourinhos

  3. 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.

  4. Occupational Exposure at a Contemplated Belarussian Power Plant Fired with Contaminated Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, K.G.; Fogh, C.L.; Roed, J

    1999-07-01

    To meet the current demand in Belarus for remediation of the vast forest areas that were contaminated by the Chernobyl accident and at the same time establish a much needed energy production, applying contaminated forest biomass as fuel in special power plants is being considered. This paper focuses on the radiation doses that may be received by workers at such a power plant. By Monte Carlo modelling based on a Danish biofuel power plant design it was found that the highest dose rates within the power plant would be those to people standing near the fly ash silo, bottom ash containers and so-called 'big bags' filled with fly ash waste. Inhalation doses were estimated to be low. External doses received while working at the power plant do not appear to be highly significant compared with the doses from environmental contamination in the area where the power plant is expected to be constructed. (author)

  5. Feasibility study of a biomass-fired cogeneration plant Groningen, Netherlands

    International Nuclear Information System (INIS)

    The feasibility of the title plant is determined for district heating and electricity supply of more than 1,000 houses in Groningen, Netherlands. Also attention is paid to the feasibility of such installations in a planned area of the city. Prices and supply of several biomass resources are dealt with: prunings of parks, public and private gardens, clean wood wastes, wood wastes from forests, wood from newly planted forests, specific energy crops (willows in high densities and short cycles). Prices are calculated, including transport to the gate of the premises where the cogeneration installations is situated. For the conversion attention is paid to both the feasibility of the use of a conventional cogeneration installation (by means of a steam turbine) and the use of a new conversion technique: combined cycle of a gasification installation and a cogeneration installation. 5 figs., 5 ills., 22 tabs., 1 appendix, 33 refs

  6. Aerial biomass and possible co² emissions after a fire; case of the forest “La Primavera”, Jalisco, México

    OpenAIRE

    Pedro Antonio Domínguez Calleros; Magaly Sánchez Durán; Juan Carlos Castañeda González; Agustín Gallegos Rodríguez

    2012-01-01

    The Area of protection of Flora and Fauna “La Primavera” (APFFLP) is one of the more important protected areas in the western of the Country, and constantly suffers large damage caused by fire, such as the one happened in 2005 when approximately 11,439 ha were affected, equivalent to 37.5% of the total area. This study was conducted in an área affected by fire, where the main goals were: to estimate the timber volume, biomass, carbon and CO2 of Pinus oocarpa and Quercus spp species, which hav...

  7. International seminar on biomass and fossil fuels co-firing in power plants and heating plants in Europe; Seminaire international sur la cocombustion de biomasse et d'energies fossiles dans les centrales electriques et les chaufferies en Europe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The aim of the European commission which has fixed to 12% the share of renewable energies in the total energy consumption up to 2010, is to develop the biomass sector. Co-firing is a solution that allows to increase significantly the use of biomass because it does not require important investments. Today, about 150 power plants in Europe use co-firing. An Altener project named 'Cofiring' has ben settled in order to bring together and analyze the European experience in this domain and to sustain and rationalize the design of future projects. The conclusions of this study, coordinated by VTT Energy and which involves CARMEN (Germany), CBE (Portugal), the Danish centre for landscape and planning, ITEBE (France), KOBA (Italy), SLU (Sweden), and EVA (Austria), were presented during this international seminar. (J.S.)

  8. Wood Pellet-Fired Biomass Boiler Project at the Ketchikan Federal Building

    Energy Technology Data Exchange (ETDEWEB)

    Tomberlin, G.

    2014-06-01

    Biomass boiler systems have existed for many years, but the technology has advanced in recent decades and can now provide automated and efficient operation for a relatively modest investment. Key advances in system monitoring and control allow for lower operating costs, since the control systems run all aspects of the boiler, including feed, load reduction and even tube cleaning. These advances have made such systems economical on a small scale in situations where inexpensive fuels like natural gas are not available. This creates an opportunity for building operators in remote, cold-climate locations to reduce the use of expensive fuels for heating buildings. GSA Region 10 installed the system at the federal building in Ketchikan, Alaska and submitted the project to the Green Proving Ground (GPG) program. GSA's GPG program contracted with the National Renewable Energy Laboratory (NREL) to assess the installation and the technology. The system serves as a demonstration to assess actual system efficiencies, as well as operating characteristics and financial benefits. In addition to installation and operational issues, the project team/researchers examined other issues, including fuel transportation costs, building energy savings, and overall economics.

  9. Biomass burning impact on PM2.5 over the southeastern US during 2007: integrating chemically speciated FRM filter measurements, MODIS fire counts and PMF analysis

    Directory of Open Access Journals (Sweden)

    R. J. Weber

    2010-03-01

    Full Text Available Archived Federal Reference Method (FRM Teflon filters used by state regulatory agencies for measuring PM2.5 mass were acquired from 15 sites throughout the southeastern US and analyzed for Water-Soluble Organic Carbon (WSOC, water-soluble ions and carbohydrates to investigate biomass burning contributions to fine aerosol mass. Based on over 900 filters that spanned all of 2007, levoglucosan and K+ were studied in conjunction with MODIS Aqua fire count data to compare their performances as biomass burning tracers. Levoglucosan concentrations exhibited a distinct seasonal variation with large enhancement in winter and spring and a minimum in summer, and were well correlated with fire counts, except in winter when residential wood burning contributions were significant. In contrast, K+ concentrations had no apparent seasonal trend and poor correlation with fire counts. Levoglucosan and K+ only correlated well in winter (r2=0.59 when biomass burning emissions were highest, whereas in other seasons they were not correlated due to the presence of other K+ sources. Levoglucosan also exhibited larger spatial variability than K+. Both species were higher in urban than rural sites (mean 44% higher for levoglucosan and 86% for K+. Positive Matrix Factorization (PMF was applied to analyze PM2.5 sources and four factors were resolved: biomass burning, refractory material, secondary light absorbing WSOC and secondary sulfate/WSOC. The biomass burning source contributed 13% to PM2.5 mass annually, 27% in winter, and less than 2% in summer, consistent with other souce apportionment studies based on levoglucosan, but lower in summer compared to studies based on K+.

  10. Biomass burning impact on PM 2.5 over the southeastern US during 2007: integrating chemically speciated FRM filter measurements, MODIS fire counts and PMF analysis

    Directory of Open Access Journals (Sweden)

    R. J. Weber

    2010-07-01

    Full Text Available Archived Federal Reference Method (FRM Teflon filters used by state regulatory agencies for measuring PM2.5 mass were acquired from 15 sites throughout the southeastern US and analyzed for water-soluble organic carbon (WSOC, water-soluble ions and carbohydrates to investigate biomass burning contributions to fine aerosol mass. Based on over 900 filters that spanned all of 2007, levoglucosan and K+ were studied in conjunction with MODIS Aqua fire count data to compare their performances as biomass burning tracers. Levoglucosan concentrations exhibited a distinct seasonal variation with large enhancement in winter and spring and a minimum in summer, and were well correlated with fire counts, except in winter when residential wood burning contributions were significant. In contrast, K+ concentrations had no apparent seasonal trend and poor correlation with fire counts. Levoglucosan and K+ only correlated well in winter (r2=0.59 when biomass burning emissions were highest, whereas in other seasons they were not correlated due to the presence of other K+ sources. Levoglucosan also exhibited larger spatial variability than K+. Both species were higher in urban than rural sites (mean 44% higher for levoglucosan and 86% for K+. Positive Matrix Factorization (PMF was applied to analyze PM2.5 sources and four factors were resolved: biomass burning, refractory material, secondary light absorbing WSOC and secondary sulfate/WSOC. The biomass burning source contributed 13% to PM2.5 mass annually, 27% in winter, and less than 2% in summer, consistent with other souce apportionment studies based on levoglucosan, but lower in summer compared to studies based on K+.

  11. 生物质直燃发电机组性能测试与(火用)分析%PERFORMANCE TEST AND EXERGY ANALYSIS FOR BIOMASS DIRECTLY FIRED POWER GENERAOR

    Institute of Scientific and Technical Information of China (English)

    晋宏师; 顾春伟

    2012-01-01

    Based on one 30MW biomass directly fired power plant with high temperature and pressure, the test on the biomass specially fired 130T/h boiler with water cooled vibrating grate was carried out under 6 different work conditions, the thermal efficiency was calculated and it was found that the main reason for efficiency deviation was higher temperature of flue gas and bad quality of the fuel. The 30MW condensed steam turbine was tested, the heat consumption was calculated and it was found that the more high heat consumption was mainly because of higher back pressure. The thermal efficiency of whole plant was calculated and it was shown that the efficiency rose when the unit output rate rose. The exergy analysis of real thermal cycle was carried out, and it was found that the exergy loss of heat transfer between flue gas and water with different temperature and combustion process were the most important factors.%以设计燃料为棉花秸秆的某30MW高温高压生物质直燃发电项目作为研究对象,在6个不同工况下,对额定蒸发量为130t/h的生物质燃烧专用水冷振动炉排锅炉进行测试,对锅炉热效率进行计算,发现锅炉热效率小于设计值的主要原因是排烟温度偏高和燃料成分差异.对30MW纯凝汽式汽轮机进行测试,对汽轮机热耗进行计算,发现汽轮机热耗小于设计值的主要原因是背压偏高.对全厂热效率进行计算,发现随着功率的增加,热效率呈增加趋势.对热力循环过程进行(火用)分析,发现在锅炉内的温差换热和燃烧环节(火用)损失最大.

  12. Biomass energy conversion: conventional and advanced technologies

    International Nuclear Information System (INIS)

    Increasing interest in biomass energy conversion in recent years has focused attention on enhancing the efficiency of technologies converting biomass fuels into heat and power, their capital and operating costs and their environmental emissions. Conventional combustion systems, such as fixed-bed or grate units and entrainment units, deliver lower efficiencies (<25%) than modem coal-fired combustors (30-35%). The gasification of biomass will improve energy conversion efficiency and yield products useful for heat and power generation and chemical synthesis. Advanced biomass gasification technologies using pressurized fluidized-bed systems, including those incorporating hot-gas clean-up for feeding gas turbines or fuel cells, are being demonstrated. However, many biomass gasification processes are derivatives of coal gasification technologies and do not exploit the unique properties of biomass. This paper examines some existing and upcoming technologies for converting biomass into electric power or heat. Small-scale 1-30 MWe units are emphasized, but brief reference is made to larger and smaller systems, including those that bum coal-biomass mixtures and gasifiers that feed pilot-fuelled diesel engines. Promising advanced systems, such as a biomass integrated gasifier/gas turbine (BIG/GT) with combined-cycle operation and a biomass gasifier coupled to a fuel cell, giving cycle efficiencies approaching 50% are also described. These advanced gasifiers, typically fluid-bed designs, may be pressurized and can use a wide variety of biomass materials to generate electricity, process steam and chemical products such as methanol. Low-cost, disposable catalysts are becoming available for hot-gas clean-up (enhanced gas composition) for turbine and fuel cell systems. The advantages, limitations and relative costs of various biomass gasifier systems are briefly discussed. The paper identifies the best known biomass power projects and includes some information on proposed and

  13. Atmospheric CH4 and CO2 enhancements and biomass burning emission ratios derived from satellite observations of the 2015 Indonesian fire plumes

    Science.gov (United States)

    Parker, Robert J.; Boesch, Hartmut; Wooster, Martin J.; Moore, David P.; Webb, Alex J.; Gaveau, David; Murdiyarso, Daniel

    2016-08-01

    The 2015-2016 strong El Niño event has had a dramatic impact on the amount of Indonesian biomass burning, with the El Niño-driven drought further desiccating the already-drier-than-normal landscapes that are the result of decades of peatland draining, widespread deforestation, anthropogenically driven forest degradation and previous large fire events. It is expected that the 2015-2016 Indonesian fires will have emitted globally significant quantities of greenhouse gases (GHGs) to the atmosphere, as did previous El Niño-driven fires in the region. The form which the carbon released from the combustion of the vegetation and peat soils takes has a strong bearing on its atmospheric chemistry and climatological impacts. Typically, burning in tropical forests and especially in peatlands is expected to involve a much higher proportion of smouldering combustion than the more flaming-characterised fires that occur in fine-fuel-dominated environments such as grasslands, consequently producing significantly more CH4 (and CO) per unit of fuel burned. However, currently there have been no aircraft campaigns sampling Indonesian fire plumes, and very few ground-based field campaigns (none during El Niño), so our understanding of the large-scale chemical composition of these extremely significant fire plumes is surprisingly poor compared to, for example, those of southern Africa or the Amazon.Here, for the first time, we use satellite observations of CH4 and CO2 from the Greenhouse gases Observing SATellite (GOSAT) made in large-scale plumes from the 2015 El Niño-driven Indonesian fires to probe aspects of their chemical composition. We demonstrate significant modifications in the concentration of these species in the regional atmosphere around Indonesia, due to the fire emissions.Using CO and fire radiative power (FRP) data from the Copernicus Atmosphere Service, we identify fire-affected GOSAT soundings and show that peaks in fire activity are followed by subsequent large

  14. Operation related on-line measurements of low temperature fire side corrosion during co-combustion of biomass and oil; Driftrelaterad direktmaetning av laagtemperaturkorrosion i en braensleeldad kraftvaermeanlaeggning

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Thomas [Studsvik Nuclear AB, Nykoeping (Sweden)

    2000-05-01

    A number of combustion plants have experienced corrosion attack on air preheaters and economisers when fired with biomass fuels. In certain plants the problems are great and reconstruction has been performed so that exposed components can be exchanged during operation. The electrochemical techniques offer on-line measurements of the changes in corrosion rate in the low temperature region in a waste incinerator. The purpose with this study was to evaluate the technique in a biomass fired boiler where the corrosion rate is considerable lower compared to a waste incinerator. Experiments were performed at the Haesselby plant, boiler 3, which was fired with pure biomass as well as a mixture of biomass and oil during the test period. It was found that the electrochemical technique is a useful tool for on-line measurements of the changes in corrosion rate in biomass fired utilities. Since the corrosion rate in the low temperature region is dependent on the boiler construction, electrochemical measurements give valuable information on the corrosion rate during optimisation of the fuel mixture, SNCR and temperature or the low temperature components. This is of special importance when introducing new fuels or fuel mixtures. Soot blowing is of prime importance for the total corrosion. During a few minutes an individual soot blower can initiate such a high corrosion rate that it represents the total corrosion. The material temperature is another important parameter. Above a certain temperature the corrosion rate is negligible. During co-combustion this temperature was found to be in the region 65-85 deg C. The influence of the SNCR with ammonia, with respect to corrosion, is dependent on the fuel mixture used. In utilities where acidic combustion products are formed, ammonia has a neutralising effect e.g. in Hoegdalen. At the Haesselby plant this neutralising effect was not found. During cocombustion with oil the ammonia forms ammoniahydrosulphate which increases the corrosion

  15. A New Agro/Forestry Residues Co-Firing Model in a Large Pulverized Coal Furnace: Technical and Economic Assessments

    Directory of Open Access Journals (Sweden)

    Shien Hui

    2013-08-01

    Full Text Available Based on the existing biomass co-firing technologies and the known innate drawbacks of dedicated biomass firing, including slagging, corrosion and the dependence on fuel, a new model of agro/forestry residue pellets/shreds and coal co-fired in a large Pulverized Coal (PC furnace was proposed, and the corresponding technical and economic assessments were performed by co-firing testing in a 300 MW PC furnace and discounted cash flow technique. The developed model is more dependent on injection co-firing and combined with co-milling co-firing. Co-firing not only reduces CO2 emission, but also does not significantly affect the fly ash use in cement industry, construction industry and agriculture. Moreover, economic assessments show that in comparison with dedicated firing in grate furnace, agro/forestry residues and coal co-firing in a large PC furnace is highly economic. Otherwise, when the co-firing ratio was below 5 wt%, the boiler co-firing efficiency was 0.05%–0.31% higher than that of dedicated PC combustion, and boiler efficiencies were about 0.2% higher with agro/forestry residues co-firing in the bottom and top burner systems than that in a middle burner system.

  16. CFD simulation of wood chip combustion on a grate using an Euler-Euler approach

    Science.gov (United States)

    Kurz, D.; Schnell, U.; Scheffknecht, G.

    2012-04-01

    Due to the increase of computational power, it is nowadays common practice to use CFD calculations for various kinds of firing systems in order to understand the internal physical phenomena and to optimise the overall process. Within the last years, biomass combustion for energy purposes has gained rising popularity. On an industrial scale, mainly grate firing systems are used for this purpose. Generally, such systems consist of a dense-packed fuel bed on the grate and the freeboard region above, where in the field of numerical modelling, it is common practice to use different sub-models for both zones. To avoid this, the objective of this paper is the presentation of a numerical model including a detailed three-dimensional description of the fuel bed and the freeboard region within the same CFD code. Because of the implementation as an Eulerian multiphase model, both zones are fully coupled in terms of flow and heat transfer, and appropriate models for the treatment of turbulence, radiation, and global reactions are presented. The model results are validated against detailed measurements of temperature and gaseous species close to the bed surface and within the radiative section of a 240 kW grate firing test facility.

  17. Measurement of temperature conditions in grate zone of a 1 MW wood-pellets boiler fired with high ash content wood-pellets

    OpenAIRE

    Skotland, Christer Heen

    2009-01-01

    The combustion of biomass could in some cases lead to ash problems induced by high temperatures such as ash sintering, agglomeration and melting. The degrees of these problems depend on the fuel feedstock and are highly dependent on the amount of potassium, sodium and chlorine in the biomass. Straw, grass, bark, branches and wood residues are typical examples of biomass fuels that are connected to the mentioned ash problems.Addition of additives in the problematic fuels is a possible measure ...

  18. The Tropical Forest and Fire Emissions Experiment: method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning

    Directory of Open Access Journals (Sweden)

    T. G. Karl

    2007-11-01

    Full Text Available Volatile Organic Compound (VOC emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS, Fourier Transform Infrared Spectroscopy (FTIR and gas chromatography (GC coupled to PTRMS (GC-PTR-MS. We investigated VOC emissions from 19 controlled laboratory fires at the USFS (United States Forest Service Fire Sciences Laboratory and 16 fires during an intensive airborne field campaign during the peak of the burning season in Brazil in 2004. The VOC emissions were dominated by oxygenated VOCs (OVOC (OVOC/NMHC ~4:1, NMHC: non-methane hydrocarbons The specificity of the PTR-MS instrument, which measures the mass to charge ratio of VOCs ionized by H3O+ ions, was validated by gas chromatography and by intercomparing in-situ measurements with those obtained from an open path FTIR instrument. Emission ratios for methyl vinyl ketone, methacrolein, crotonaldehyde, acrylonitrile and pyrrole were measured in the field for the first time. Our measurements show a higher contribution of OVOCs than previously assumed for modeling purposes. Comparison of fresh (<15 min and aged (>1 h–1 d smoke suggests altered emission ratios due to gas phase chemistry for acetone but not for acetaldehyde and methanol. Emission ratios for numerous, important, reactive VOCs with respect to acetonitrile (a biomass burning tracer are presented.

  19. The tropical forest and fire emissions experiment: method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning

    Directory of Open Access Journals (Sweden)

    T. G. Karl

    2007-06-01

    Full Text Available Volatile Organic Compound (VOC emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS, Fourier Transformation Infrared Spectroscopy (FTIR and gas chromatography (GC coupled to PTRMS (GC-PTR-MS. We investigated VOC emissions from 19 controlled laboratory fires at the USFS Fire Sciences Laboratory and 16 fires during an intensive airborne field campaign during the peak of the burning season in Brazil in 2004. The VOC emissions were dominated by oxygenated VOCs (OVOC (OVOC/NMHC ~4:1, NMHC: non-methane hydrocarbons The specificity of the PTR-MS instrument, which measures the mass to charge ratio of VOCs ionized by H3O+ ions, was validated by gas chromatography and by intercomparing in-situ measurements with those obtained from an open path FTIR instrument. Emission ratios for methyl vinyl ketone, methacrolein, crotonaldehyde, acrylonitrile and pyrrole were measured in the field for the first time. Our measurements show a higher contribution of OVOCs than previously assumed for modeling purposes. Comparison of fresh (<15 min and aged (>1hour-1day smoke suggests altered emission ratios due to gas phase chemistry for acetone but not for acetaldehyde and methanol. Emission ratios for numerous, important, reactive VOCs with respect to acetonitrile (a biomass burning tracer are presented.

  20. Improved biomass and lipid production in a mixotrophic culture of Chlorella sp. KR-1 with addition of coal-fired flue-gas.

    Science.gov (United States)

    Praveenkumar, Ramasamy; Kim, Bohwa; Choi, Eunji; Lee, Kyubock; Park, Ji-Yeon; Lee, Jin-Suk; Lee, Young-Chul; Oh, You-Kwan

    2014-11-01

    Industrial CO2-rich flue-gases, owing to their eco-toxicity, have yet to be practically exploited for microalgal biomass and lipid production. In this study, various autotrophic and mixotrophic culture modes for an oleaginous microalga, Chlorella sp. KR-1 were compared for the use in actual coal-fired flue-gas. Among the mixotrophic conditions tested, the fed-batch feedings of glucose and the supply of air in dark cycles showed the highest biomass (561 mg/L d) and fatty-acid methyl-ester (168 mg/L d) productivities. This growth condition also resulted in the maximal population of microalgae and the minimal population and types of KR-1-associated-bacterial species as confirmed by particle-volume-distribution and denaturing-gradient-gel-electrophoresis (DGGE) analyses. Furthermore, microalgal lipid produced was assessed, based on its fatty acid profile, to meet key biodiesel standards such as saponification, iodine, and cetane numbers.

  1. Fundamental mechanisms for conversion of volatiles in biomass and waste combustion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Glarborg, P.; Hindiyarti, L.; Marshall, P.; Livbjerg, H.; Dagaut, P.; Jensen, Anker; Frandsen, Flemming

    2007-03-15

    This project deals with the volatile oxidation chemistry in biomass and waste fired systems, emphasizing reactions important for pollutants emissions (NO{sub x}, SO{sub 2}, HCl, aerosols). The project aims to extend existing models and databases with a number of chemical subsystems that are presently not well understood, but are particularly important in connection with combustion of biomass and waste. The project is divided into 3 tasks. Task 1: Conversion of chlorine, sulfur and alkali gas phase components in combustion of biomass. Task 2: Formation mechanisms for NO{sub x} in the freeboard of grate combustion of biomass. Task 3: Oxidation mechanisms for oxygenated hydrocarbons in the volatiles from pyrolysis of biomass. (au)

  2. A Research on Structure Design of Small Biomass Direct-fired Stove%小型生物质直燃炉结构设计

    Institute of Scientific and Technical Information of China (English)

    石毅新; 蒋蘋; 彭才望

    2015-01-01

    At present,the biomass-fire stove is still with so much problems, such as the low combustion efficiency and excessive generation of tar during the combustion , buring thin layer with high the combustion efficiency , serves as the main buring mode of the small biomass-fire stove which greatly increase combustion efficiency and effectively reduce the generation of tar and dust and it applys screw conveyor to feed the hearth continuously to keep it burning stably and continuously. Which plays a positive role in handling the waste of biomass fuel waste and environmental pollution successfully in rural areas and offers a thought for the sustainable energy development under the new situation.%基于目前现有生物质燃烧炉的燃烧效率低,且燃烧过程中焦油生成过多等问题。以高效率燃烧方式的薄层燃烧为该小型生物质直燃炉的主要燃烧方式,大大提高燃烧效率的同时,有效较低焦油与烟尘的产生,并且采用螺杆输送装置对炉膛进行持续供料,实现稳定的不间断燃烧,为成功解决农村生物质燃料浪费及环境污染起到积极作用,为新形势下的能源可持续发展提供思路。

  3. Aerial biomass and possible co² emissions after a fire; case of the forest “La Primavera”, Jalisco, México

    Directory of Open Access Journals (Sweden)

    Pedro Antonio Domínguez Calleros

    2012-09-01

    Full Text Available The Area of protection of Flora and Fauna “La Primavera” (APFFLP is one of the more important protected areas in the western of the Country, and constantly suffers large damage caused by fire, such as the one happened in 2005 when approximately 11,439 ha were affected, equivalent to 37.5% of the total area. This study was conducted in an área affected by fire, where the main goals were: to estimate the timber volume, biomass, carbon and CO2 of Pinus oocarpa and Quercus spp species, which have a larger significant value in the ecology of the area. A network of 56 sampling sites was measured; these were 500 m2 circular sites (radius 12.61 m, spaced every 100 m. At each site, just dead trees (either cut or standing with at least 7 cm of diameter at breast height (DBH were measured, taking the basal area as the main parameter. From the data, allometric models were generated to estimate the volume, depending on the measurement of DBH. The determination coefficient R2 for Pinus oocarpa was 0.87995 being the exponential regression model the one with the best fit; The valuation of the biomass was 40,43 T/ha, that multiplied by the fraction of the carbon recommended for the species studied in this region is equivalent to 20,2 T/ha, giving a value of 74,1 T/ha of CO2. In the case of Quercus spp it showed a R of 0.87571, being the linear regression model the best adjusted, with an average of 26.5 T/ha of biomass, meaning a carbon estimation of 13.24 T/ha equivalent to a total of 48.62 T/ha of CO2 if it were emitted into theatmosphere.

  4. Material problems related to large scale firing of biomass. Steam oxidation of TP 347H FG and X20

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2009-07-01

    TP 347 H and X20 is often used as construction material in biomass-fired boilers. The corrosion rate of the alloys is affected by the metal temperature. In this project, the oxidation behaviour of TP 347H FG and X20 is studied by field-testing, laboratory exposures, and thermodynamic/kinetic modelling. The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in 4 test superheater loops in a coal-fired power plant. The steel was exposed for 7720, 22985, 29588, and 57554 h at metal temperatures between 499 and 650 deg. C. In the laboratory furnace, the oxidation behaviour of TP 347H FG, TP 347H CG, and X20 was studied in water vapour containing environments (8 or 46%) in the temperature range 500-700 deg. C. Air, Ar and Ar+7% H{sub 2} were used as carrier gas. The microstructure of the oxide layer and the subjacent alloy was investigated with X-ray diffraction (XRD), reflective light microscopy (RLM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) equipped with electron diffraction (ED) and EDS. Double-layered oxides developed during steam oxidation of TP 347H FG both during field-testing and during laboratory exposures. TEM investigation suggested that the interior of the alloy grain was oxidised internally, forming particles of metallic Ni/Fe and Fe-Cr spinel. A FeCr{sub 2}O{sub 4} layer developed along the former alloy grain boundaries. Cr{sub 2}O{sub 3} developed in between this layer and the alloy during field-testing, and its formation was promoted by higher temperature. The morphology of the inner layer for the samples oxidised below and above approx. 585 deg. C looked very different in SEM (field-testing). It is suggested that more Cr is incorporated into the oxide layer at higher temperature, gradually transforming the morphology of the inner oxide layer. The alloy beneath the oxide layer was depleted in Cr

  5. Material problems related to large scale firing of biomass. Steam oxidation of TP 347H FG and X20

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2009-07-01

    TP 347 H and X20 is often used as construction material in biomass-fired boilers. The corrosion rate of the alloys is affected by the metal temperature. In this project, the oxidation behaviour of TP 347H FG and X20 is studied by field-testing, laboratory exposures, and thermodynamic/kinetic modelling. The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in 4 test superheater loops in a coal-fired power plant. The steel was exposed for 7720, 22985, 29588, and 57554 h at metal temperatures between 499 and 650 deg. C. In the laboratory furnace, the oxidation behaviour of TP 347H FG, TP 347H CG, and X20 was studied in water vapour containing environments (8 or 46%) in the temperature range 500-700 deg. C. Air, Ar and Ar+7% H{sub 2} were used as carrier gas. The microstructure of the oxide layer and the subjacent alloy was investigated with X-ray diffraction (XRD), reflective light microscopy (RLM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) equipped with electron diffraction (ED) and EDS. Double-layered oxides developed during steam oxidation of TP 347H FG both during field-testing and during laboratory exposures. TEM investigation suggested that the interior of the alloy grain was oxidised internally, forming particles of metallic Ni/Fe and Fe-Cr spinel. A FeCr{sub 2}O{sub 4} layer developed along the former alloy grain boundaries. Cr{sub 2}O{sub 3} developed in between this layer and the alloy during field-testing, and its formation was promoted by higher temperature. The morphology of the inner layer for the samples oxidised below and above approx. 585 deg. C looked very different in SEM (field-testing). It is suggested that more Cr is incorporated into the oxide layer at higher temperature, gradually transforming the morphology of the inner oxide layer. The alloy beneath the oxide layer was depleted in Cr

  6. Fire Radiative Power (FRP)-based Emission Factors of PM2.5, CO and NOX for Remote Sensing of Biomass Burning Emissions

    Science.gov (United States)

    Karandana Gamalathge, T. D.; Chen, L. W. A.

    2015-12-01

    Large-scale biomass burning such as forest fires represents an important and yet uncertain source of air pollutants and greenhouse gases on a global scale. Due to the highly accidental nature of forest fires, satellite remote sensing could be a promising method to develop regional and global fire emission inventories on a real-time basis. Reliable fire radiative power (FRP)-based fuel consumption and emission factors are critical in this approach. In an attempt to obtain the information, laboratory combustion experiments were conducted to simultaneously monitor FRP, fuel consumption, and emissions of fine particulate matter (PM2.5), carbon monoxide (CO), and reactive nitrogen oxides (NO and NO2). FRP were quantified using temperature-resolved values from a thermal imager instead of conventionally used average temperature, as the former provides more realistic estimates. For dry Ponderosa pine branches, a common fuel in the Sierra Nevada, a strong correlation (r2 ~ 0.8) between FRP and the mass reduction rate (MRR) was found. This led to a radiative energy yield (REY) of 8.5 ± 1.2 MJ/kg, assuming blackbody radiation and a flame emissivity of 0.5. Mass-based emission factors were determined with the carbon balance approach. Considering the ratio of mass-based emission factors and the REY, FRP-based emission factors: PM2.5: 11 g/MJ, CO: 8.0 g/MJ, NO: 0.33 g/MJ, and NO2: 0.07 g/MJ were quantified. The application of this approach to other fuel types and uncertainties in the measurements will be discussed.

  7. Field test corrosion experiments in Denmark with biomass fuels Part II Co-firing of straw and coal

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Larsen, OH

    2002-01-01

    and potassium sulphate. These components give rise to varying degrees of accelerated corrosion. This paper concerns co-firing of straw with coal to reduce the corrosion rate from straw to an acceptable level. A field investigation at Midtkraft Studstrup suspension-fired power plant in Denmark has been......In Denmark, straw is used for generating energy in power plants. However during straw combustion, potassium chloride and SO2 are released in the flue gas and through condensation and deposition processes they will result in the formation of superheater deposits rich in potassium chloride...... undertaken where coal has been co-fired with 10% straw and 20% straw (% energy basis) for up to approx. 3000 hours. Two types of exposure were undertaken to investigate corrosion: a) the exposure of metal rings on water/air cooled probes, and b) the exposure of a range of materials built into the existing...

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

    Directory of Open Access Journals (Sweden)

    Smajevic Izet

    2012-01-01

    Full Text Available This paper presents the findings of research into cofiring two Bosnian cola types, brown coal and lignite, with woody biomass, in this case spruce sawdust. The aim of the research was to find the optimal blend of coal and sawdust that may be substituted for 100% coal in large coal-fired power stations in Bosnia and Herzegovina. Two groups of experimental tests were performed in this study: laboratory testing of co-firing and trial runs on a large-scale plant based on the laboratory research results. A laboratory experiment was carried out in an electrically heated and entrained pulverized-fuel flow furnace. Coal-sawdust blends of 93:7% by weight and 80:20% by weight were tested. Co-firing trials were conducted over a range of the following process variables: process temperature, excess air ratio and air distribution. Neither of the two coal-sawdust blends used produced any significant ash-related problems provided the blend volume was 7% by weight sawdust and the process temperature did not exceed 1250ºC. It was observed that in addition to the nitrogen content in the co-fired blend, the volatile content and particle size distribution of the mixture also influenced the level of NOx emissions. The brown coal-sawdust blend generated a further reduction of SO2 due to the higher sulphur capture rate than for coal alone. Based on and following the laboratory research findings, a trial run was carried out in a large-scale utility - the Kakanj power station, Unit 5 (110 MWe, using two mixtures; one in which 5%/wt and one in which 7%/wt of brown coal was replaced with sawdust. Compared to a reference firing process with 100% coal, these co-firing trials produced a more intensive redistribution of the alkaline components in the slag in the melting chamber, with a consequential beneficial effect on the deposition of ash on the superheater surfaces of the boiler. The outcome of the tests confirms the feasibility of using 7%wt of sawdust in combination

  9. Estimating aboveground forest biomass carbon and fire consumption in the U.S. Utah High Plateaus using data from the Forest Inventory and Analysis program, Landsat, and LANDFIRE

    Science.gov (United States)

    Chen, X.; Liu, S.; Zhu, Z.; Vogelmann, J.; Li, Z.; Ohlen, D.

    2011-01-01

    The concentrations of CO2 and other greenhouse gases in the atmosphere have been increasing and greatly affecting global climate and socio-economic systems. Actively growing forests are generally considered to be a major carbon sink, but forest wildfires lead to large releases of biomass carbon into the atmosphere. Aboveground forest biomass carbon (AFBC), an important ecological indicator, and fireinduced carbon emissions at regional scales are highly relevant to forest sustainable management and climate change. It is challenging to accurately estimate the spatial distribution of AFBC across large areas because of the spatial heterogeneity of forest cover types and canopy structure. In this study, Forest Inventory and Analysis (FIA) data, Landsat, and Landscape Fire and Resource Management Planning Tools Project (LANDFIRE) data were integrated in a regression tree model for estimating AFBC at a 30-m resolution in the Utah High Plateaus. AFBC were calculated from 225 FIA field plots and used as the dependent variable in the model. Of these plots, 10% were held out for model evaluation with stratified random sampling, and the other 90% were used as training data to develop the regression tree model. Independent variable layers included Landsat imagery and the derived spectral indicators, digital elevation model (DEM) data and derivatives, biophysical gradient data, existing vegetation cover type and vegetation structure. The cross-validation correlation coefficient (r value) was 0.81 for the training model. Independent validation using withheld plot data was similar with r value of 0.82. This validated regression tree model was applied to map AFBC in the Utah High Plateaus and then combined with burn severity information to estimate loss of AFBC in the Longston fire of Zion National Park in 2001. The final dataset represented 24 forest cover types for a 4 million ha forested area. We estimated a total of 353 Tg AFBC with an average of 87 MgC/ha in the Utah High

  10. Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-01

    The main constituents rendering the engine use of gas produced from biomass are the tar content of the gases (condensing hydrocarbons), which cause problems for pipings, nozzles, and control of combustion. Purification methods, based on catalytic cracking of tars are investigated in the research in order to eliminate these problems. The target of the project is to demonstrate the developed gasification/gas purification process with engine test using PDU-scale equipment. Impurities of biomasses and biomass wastes (alkalis, chlorine, heavy metals), and the ash melting properties restrict in many cases the combined utilisation of biomasses and coal in power plant boilers. The second main task of this research is to investigate the removal of the problematic gas and ash components from the product gas. The sufficient degree of purification should be achieved by as simple and as cheap purification methods as possible. The main tasks of the first year of the project were (a) determination of the dimensioning characteristics of ambient pressure PDU scale cell-catalyst reactor (tests with laboratory-scale equipment), designing and construction of the reactor, (b) to investigate the operation of a cell-catalyst in purification of pre-cracked down-draft gasification gas, (c) acquisition of dimensioning data for dolomite-cracker based on fluidized bed principle, and (d) gasification of the Dutch building demolition waste and Danish straw, and the purification tests with the gases

  11. Towards a CFD-based mechanistic deposit formation model for straw-fired boilers

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen; Rosendahl, Lasse Aistrup; Baxter, L.L.

    2006-01-01

    This paper discusses the application of FLUENTe in the analysis of grate-fired biomass boilers. A short description of the concept used to model fuel conversion on the grate and the coupling to the CFD code is offered. The development and implementation of a CFD-based deposition model is presented...... in the reminder of the paper. The growth of deposits on furnace walls and super heater tubes is treated including the impact on heat transfer rates determined by the CFD code. Based on the commercial CFD code FLUENTe, the overall model is fully implemented through the User Defined Functions. The model...... resistance changes. The model is applied to the straw-fired Masnedø boiler. Results are in good qualitative agreement with both measurements and observations at the plants. q 2005 Elsevier Ltd. All rights reserved....

  12. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    International Nuclear Information System (INIS)

    This is the third Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Three additional biomass co-firing test burns have been conducted. In the first test (Test 3), up to 20% by weight dry hardwood sawdust and dry switchgrass was injected through the center of the burner. In the second test (Test 4), 100% Pratt seam coal was burned in a repeat of the initial test condition of Test 1, to reconcile irregularities in the data from the first test. In the third test (Test 5), up to 20% by weight dry hardwood sawdust and dry switchgrass was injected through an external pipe directed toward the exit of the burner. Progress has continued in developing a modeling approach to synthesize the reaction time and temperature distributions that will be produced by computational fluid dynamic models of the pilot-scale combustion furnace and the char burnout and chemical reaction kinetics that will predict NOx emissions and unburned carbon levels in the furnace exhaust. Additional results of CFD modeling efforts have been received and Preparations are under way for continued pilot-scale combustion experiments. Finally, a presentation was made at a Biomass Cofiring Project Review Meeting held at the NETL in Pittsburgh, PA on June 20-21

  13. Experimental investigation on NOx reduction by primary measures in biomass combustion: straw, peat, sewage sludge, forest residues and wood pellets

    OpenAIRE

    Øyvind Skreiberg; Ehsan Houshfar; Terese Løvås

    2012-01-01

    An experimental investigation was carried out to study the NOx formation and reduction by primary measures for five types of biomass (straw, peat, sewage sludge, forest residues/Grot, and wood pellets) and their mixtures. To minimize the NOx level in biomass-fired boilers, combustion experiments were performed in a laboratory scale multifuel fixed grate reactor using staged air combustion. Flue gas was extracted to measure final levels of CO, CO2, CxHy, O2, NO, NO2, N2O, and other species. Th...

  14. Experimental Investigation on NOx Reduction by Primary Measures in Biomass Combustion: Straw, Peat, Sewage Sludge, Forest Residues and Wood Pellets

    OpenAIRE

    Houshfar, Ehsan; Løvås, Terese; Skreiberg, Øyvind

    2012-01-01

    An experimental investigation was carried out to study the NOx formation and reduction by primary measures for five types of biomass (straw, peat, sewage sludge, forest residues/Grot, and wood pellets) and their mixtures. To minimize the NOx level in biomass-fired boilers, combustion experiments were performed in a laboratory scale multifuel fixed grate reactor using staged air combustion. Flue gas was extracted to measure final levels of CO, CO2, CxHy, O2, NO, NO2, N2O, and other species. Th...

  15. Fine particulate matter associated with monsoonal effect and the responses of biomass fire hotspots in the tropical environment

    Directory of Open Access Journals (Sweden)

    M. F. Khan

    2015-08-01

    Full Text Available The health implications of PM2.5 in tropical regions of Southeast Asia are significant as PM2.5 can pose serious health concerns. PM2.5 is strongly influenced by the monsoon. We quantitatively characterize the health risks posed to human populations by selected heavy metals in PM2.5. Monsoonal effects as well as factors influencing the sources of PM2.5 were also determined. Apportionment analysis of PM2.5 was undertaken using US EPA positive matrix factorization (PMF 5.0 and a mass closure model. Overall, 48 % of the samples exceeded the World Health Organization (WHO 24 h guideline. The mass closure model identified four sources of PM2.5: (a mineral matter (MIN (35 %, (b secondary inorganic aerosol (SIA (11 %, (c sea salt (SS (7 %, (d trace elements (TE (2 % and (e undefined (UD (45 %. PMF 5.0 identified five potential sources and motor vehicle emissions and biomass burning were dominant followed by marine and sulfate aerosol, coal burning, nitrate aerosol, and mineral and road dust. The non-carcinogenic risk level for four selected metals (Pb, As, Cd and Ni in PM2.5 and in the identified major sources by PMF > 5.0, with respect to inhalation follows the order of PM2.5 > coal burning > motor vehicle emissions/biomass burning > mineral/road dust. The lifetime cancer risk follows the order of As > Ni > Pb > Cd for mineral/road dust, coal burning and overall of PM2.5 concentration and As > Pb > Ni > Cd for motor vehicle/biomass burning. Overall, the associated cancer risk posed by the exposure of toxic metals in PM2.5 is three to four in 1 000 000 people in this location.

  16. Fine particulate matter associated with monsoonal effect and the responses of biomass fire hotspots in the tropical environment

    Science.gov (United States)

    Khan, M. F.; Latif, M. T.; Saw, W. H.; Amil, N.; Nadzir, M. S. M.; Sahani, M.; Tahir, N. M.; Chung, J. X.

    2015-08-01

    The health implications of PM2.5 in tropical regions of Southeast Asia are significant as PM2.5 can pose serious health concerns. PM2.5 is strongly influenced by the monsoon. We quantitatively characterize the health risks posed to human populations by selected heavy metals in PM2.5. Monsoonal effects as well as factors influencing the sources of PM2.5 were also determined. Apportionment analysis of PM2.5 was undertaken using US EPA positive matrix factorization (PMF) 5.0 and a mass closure model. Overall, 48 % of the samples exceeded the World Health Organization (WHO) 24 h guideline. The mass closure model identified four sources of PM2.5: (a) mineral matter (MIN) (35 %), (b) secondary inorganic aerosol (SIA) (11 %), (c) sea salt (SS) (7 %), (d) trace elements (TE) (2 %) and (e) undefined (UD) (45 %). PMF 5.0 identified five potential sources and motor vehicle emissions and biomass burning were dominant followed by marine and sulfate aerosol, coal burning, nitrate aerosol, and mineral and road dust. The non-carcinogenic risk level for four selected metals (Pb, As, Cd and Ni) in PM2.5 and in the identified major sources by PMF > 5.0, with respect to inhalation follows the order of PM2.5 > coal burning > motor vehicle emissions/biomass burning > mineral/road dust. The lifetime cancer risk follows the order of As > Ni > Pb > Cd for mineral/road dust, coal burning and overall of PM2.5 concentration and As > Pb > Ni > Cd for motor vehicle/biomass burning. Overall, the associated cancer risk posed by the exposure of toxic metals in PM2.5 is three to four in 1 000 000 people in this location.

  17. 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...

  18. 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.

  19. 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

  20. Investigating the links between ozone and organic aerosol chemistry in a biomass burning plume from a prescribed fire in California chaparral

    Science.gov (United States)

    Alvarado, M. J.; Lonsdale, C. R.; Yokelson, R. J.; Akagi, S. K.; Coe, H.; Craven, J. S.; Fischer, E. V.; McMeeking, G. R.; Seinfeld, J. H.; Soni, T.; Taylor, J. W.; Weise, D. R.; Wold, C. E.

    2015-06-01

    Within minutes after emission, complex photochemistry in biomass burning smoke plumes can cause large changes in the concentrations of ozone (O3) and organic aerosol (OA). Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP) to simulate the evolution of O3 and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed fire in chaparral, which was sampled over California in November 2009. We demonstrate the use of a method for simultaneously accounting for the impact of the unidentified intermediate volatility, semi-volatile, and extremely low volatility organic compounds (here collectively called "SVOCs") on the formation of OA (using the Volatility Basis Set - VBS) and O3 (using the concept of mechanistic reactivity). We show that this method can successfully simulate the observations of O3, OA, NOx, ethylene (C2H4), and OH to within measurement uncertainty using reasonable assumptions about the average chemistry of the unidentified SVOCs. These assumptions were (1) a reaction rate constant with OH of ~ 10-11 cm3 s-1; (2) a significant fraction (up to ~ 50 %) of the RO2 + NO reaction resulted in fragmentation, rather than functionalization, of the parent SVOC; (3) ~ 1.1 molecules of O3 were formed for every molecule of SVOC that reacted; (4) ~ 60 % of the OH that reacted with the unidentified non-methane organic compounds (NMOC) was regenerated as HO2; and (5) that ~ 50 % of the NO that reacted with the SVOC peroxy radicals was lost, presumably to organic nitrate formation. Additional evidence for the fragmentation pathway is provided by the observed rate of formation of acetic acid (CH3COOH), which is consistent with our assumed fragmentation rate. However, the model overestimates peroxyacetyl

  1. High temperature corrosion in biomass- and waste fired boilers. A status report; Kunskapslaeget betraeffande hoegtemperaturkorrosion i aangpannor foer biobraensle och avfall

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, P.; Ifwer, K.; Staalenheim, A.; Montgomery, M.; Hoegberg, J.; Hjoernhede, A.

    2006-12-15

    Many biomass- or waste-fired plants have problems with high temperature corrosion on the furnace walls or at the superheaters, especially if the steam temperature is greater than 500 deg C. An increase in the combustion of waste fuels means that an increasing number of boilers have had problems. Therefore, there is great interest from plant owners to reduce the costs associated with high temperature corrosion. At the same time there exists a considerable driving force towards improving the electrical efficiency of a plant by the use of more advanced steam data. The purpose of the work presented here was to answer three main questions: What can be done to reduce high temperature corrosion with current fuel blends and steam temperatures? How can more waste fuels be burnt without an increased risk for corrosion? What needs to be done to reach higher steam temperatures in the future? The level of knowledge of high temperature corrosion in biomass- and waste-fired boilers has been described and summarised. The following measures are recommended to reduce corrosion in existing plant: Make sure that the fuel is well mixed and improve fuel feeding to obtain a more even spread of the fuel over the cross-section of the boiler. Use combustion technology methods to stabilize the oxygen content of the flue gases near the membrane walls and other heat transfer surfaces. Experiment with additives and/or supplementary fuels which contain sulphur in some form, for example peat. Reduce the flue gas temperature at the superheaters. Review soot-blowing procedures or protect heat transfer surfaces from soot blowers. Evaluate coated membrane wall panels in parts of the furnace that experience the worst corrosion. Test more highly alloyed steels suitable for superheaters and when replacing a superheater change to a more highly alloyed steel. For the future, the following should be considered: The role of sulphur needs to be investigated more and other additives should be investigated

  2. Managing corrosion in biomass boilers. Benefits and limitations of coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tuurna, S.; Varis, T.; Ruusuvuori, K. (and others) (VTT Technical Research Centre of Finland, Espoo (Finland))

    2010-05-15

    Oxidation and corrosion of materials in highly demanding applications is critical for longterm performance of materials used in power generation. Energy production in biomass fired boilers is increasing rapidly due to the advantages of CO{sub 2} neutrality and renewability. Fluidised bed combustors and grate fired boilers have proved the most reliable technologies for burning biomass since its fuel characteristics are variable. The fly ash of biomass is relatively corrosive due to its composition containing high concentrations of chemically active compounds of alkali, sulphur and chlorine, and it also may contain erosive components especially in the case of fluidised bed boilers. Due to the potential for severe chlorine induced corrosion, plant operating temperatures and efficiency must be limited. To overcome material wastage more alloyed materials are needed. The high cost and sometimes hard to manufacture bulk materials could be replaced with coatings, which can be applied on the more economic low alloy steel having the proper mechanical properties. The paper discusses the benefits and limitations of thermal sprayed coatings in biomass boilers. The applied examples have included iron and nickel based HVOF and arc sprayed coatings subjected to verification field testing in boiler testing under in aggressive biofuel conditions. The coatings have shown good corrosion resistance in long-term field tests. (orig.)

  3. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    International Nuclear Information System (INIS)

    This is the sixth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 10), up to 20% by weight dry hardwood sawdust and switchgrass was compiled with Galatia coal and injected through the dual-register burner. Galatia coal is a medium-sulfur Illinois Basin coal ((approx)1.0% S). The dual-register burner is a generic low-NO(sub x) burner that incorporates two independent wind boxes. In the second test (Test 11), regular ((approx)70% passing 200 mesh) and finely ground ((approx)90% passing 200 mesh) Pratt Seam coal was injected through the single-register burner to determine if coal grind affects NO(sub x) and unburned carbon emissions. The results of these tests are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO(sub x) emissions and unburned carbon levels in the furnace exhaust. No additional results of CFD modeling have been received as delivery of the Configurable Fireside Simulator is expected during the next quarter. Preparations are under way for continued pilot-scale combustion experiments with the single-register burner and a low-volatility bituminous coal. Some delays have been experienced in the acquisition and processing of biomass. Finally, a project review was held at the offices of Southern Research in Birmingham, on February 27, 2002

  4. Influence of fuel rich zone stoichiometry on HCN and NH{sub 3} evolution during pulverized biomass co-firing

    Energy Technology Data Exchange (ETDEWEB)

    G. Di Nola; H. Spliethoff [Delft University of Technology (Netherlands). Energy Technology Section, Faculty of Mechanical, Maritime and Materials Engineering

    2005-07-01

    In The Netherlands, the Dutch government aims to enhance the energy production by co-combustion from 0.1 PJ in 1995 to 39 PJ in 2010. The aim of this work is to investigate in which way the cofiring of animal waste and the adoption of air staging affects the in-flame NOx formation. Bench scale pulverized fuel reactor experiments were carried at a furnace wall temperature of 1300{sup o}C. Hvb coal blend was fired as reference case. Chicken manure and meat and bone meal (MBM) were cofired with a target share of 20%{sub th}. The NOx emissions are considerably reduced when the stoichiometry in the primary zone equals to {gamma}{sub 1} = 0.7 - 0.9 for all cases. Chicken manure cofiring presents minimum NOx levels comparable to those of the reference coal, in spite of higher nitrogen content. As to NOx precursors evolution, HCN release shows similar patterns to the coal case, i.e. higher concentrations are achieved with lower stoichiometries. Different patterns are reported for ammonia, with higher yields recorded with intermediate stoichiometries of {gamma}{sub 1} = 0.89 and {gamma}{sub 1} = 0.79. 40 refs., 8 figs., 3 tabs.

  5. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    International Nuclear Information System (INIS)

    This is the fifth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. One additional biomass co-firing test burn was conducted during this quarter. In this test (Test 9), up to 20% by weight dry hardwood sawdust and switchgrass was injected through the center of the single-register burner with Jacobs Ranch coal. Jacobs Ranch coal is a low-sulfur Powder River Basin coal ((approx) 0.5% S). The results from Test 9 as well as for Test 8 (conducted late last quarter) are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO(sub x) emissions and unburned carbon levels in the furnace exhaust. Additional results of CFD modeling efforts have been received and preparations are under way for continued pilot-scale combustion experiments with the dual-register burner. Finally, a project review was held at NETL in Pittsburgh, on November 13, 2001

  6. Environmental risks of biomass ashes application in soils [Resumo

    OpenAIRE

    Freire, M; Lopes, M. Helena; Tarelho, L.

    2014-01-01

    This work presents the potential environmental risks of biomass ashes application in forest soils. The ashes were collected in five industrial biomass thermal plants using different technologies: bubbling fluidized bed combustor and grate furnace.

  7. Experience with the operation and fuel supply of the biomass firing plant of the Trocknungsgenossenschaft Lengenfeld eG, a drying cooperative society; Erfahrungen mit Betrieb und Brennstoffbereitstellung der Biomassefeuerung der Trocknungsgenossenschaft Lengenfeld eG

    Energy Technology Data Exchange (ETDEWEB)

    Thoma, H. [Buero fuer Agraroekonomische Gutachten, Expertisen und Projektstudien, Langenbach (Germany)

    1994-12-31

    The pilot project of the conversion of the green forage drying plant Lengenfeld to biomass firing could not be realized without problems. But the experience until now shows that it is in principle possible. The farmers involved are devoted to the project. For them the cultivation of biomass is an alternative to the abandonment of fields. The present low oil price sets limits to the positive income effect. The aim is an increase of the biomass share in heating energy supply to about 80%. (orig.) [Deutsch] Die Umstellung der Gruenfuttertrocknung Lengenfeld auf Biomassefeuerung ist als Pilotprojekt nicht ohne Probleme moeglich gewesen. Die bisherigen Erfahrungen zeigen jedoch die grundsaetzliche Praktikabilitaet. Die beteiligten Landwirte sind engagiert bei der Sache und schaetzen die Produktionsmoeglichkeit als Alternative zur Flaechenstillegung. Der derzeit niedrige Oelpreis setzt der positiven Einkommenswirkung jedoch enge Grenzen. Eine Erhoehung des Biomasseanteils an der Heizenergieversorgung auf etwa 80% ist das Ziel. (orig.)

  8. The use of ATSR active fire counts for estimating relative patterns of biomass burning- a study from the boreal forest region

    OpenAIRE

    Kasischke, Eric S; Hewson, J. H; B. J. Stocks; G. R. van der Werf; J. T. Randerson

    2003-01-01

    Satellite fire products have the potential to construct inter-annual time series of fire activity, but estimating area burned requires considering biases introduced by orbiting geometry, fire behavior, and the presence of clouds and smoke. Here we evaluated the performance of fire counts from the Advanced Thermal Scanning Radiometer (ATSR) for the boreal forest region using area burned information from other sources. We found ATSR detection rate varied between regions and different years, bei...

  9. The tropical forest and fire emissions experiment: method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning

    OpenAIRE

    T. G. Karl; T. J. Christian; Yokelson, R. J.; P. Artaxo; Hao, W. M; A. Guenther

    2007-01-01

    Volatile Organic Compound (VOC) emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS), Fourier Transform Infrared Spectroscopy (FTIR) and gas chromatography (GC) coupled to PTRMS (GC-PTR-MS). We investigated VOC emissions from 19 controlled laboratory fires at the USFS (United States Forest Service) Fire Sciences Laboratory and 16 fires during an intensive airborne field campaign during the peak of the burning season in Brazil i...

  10. Investigating the links between ozone and organic aerosol chemistry in a biomass burning plume from a prescribed fire in California chaparral

    Directory of Open Access Journals (Sweden)

    M. J. Alvarado

    2014-12-01

    Full Text Available Within minutes after emission, rapid, complex photochemistry within a biomass burning smoke plume can cause large changes in the concentrations of ozone (O3 and organic aerosol (OA. Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP to simulate the evolution of O3 and secondary organic aerosol (SOA within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, which was sampled over California in November 2009. We demonstrate the use of a method for simultaneously accounting for the impact of the unidentified semi-volatile to extremely low volatility organic compounds (here collectively called "SVOCs" on the formation of OA (using the Volatility Basis Set and O3 (using the concept of mechanistic reactivity. We show that this method can successfully simulate the observations of O3, OA, PAN, NOx, and C2H4 to within measurement uncertainty using reasonable assumptions about the chemistry of the unidentified SVOCs. These assumptions were: (1 a~reaction rate constant with OH of ~10−11cm3s−1, (2 a significant fraction (~50% of the RO2 + NO reaction resulted in fragmentation, rather than functionalization, of the parent SVOC, (3 ~1.1 molecules of O3 were formed for every molecule of SVOC that reacted, (4 ~60% of the OH that reacted with the unidentified SVOCs was regenerated as HO2, and (5 that ~50% of the NO that reacted with the SVOC peroxy radicals was lost, presumably to organic nitrate formation. Additional evidence for the fragmentation pathway is provided by the observed rate of formation of acetic acid, which is consistent with our assumed fragmentation rate. This method could provide a way for classifying different smoke plume observations in terms of the average chemistry of their SVOCs

  11. A Path Forward for Low Carbon Power from Biomass

    OpenAIRE

    Amanda D. Cuellar; Howard Herzog

    2015-01-01

    The two major pathways for energy utilization from biomass are conversion to a liquid fuel (i.e., biofuels) or conversion to electricity (i.e., biopower). In the United States (US), biomass policy has focused on biofuels. However, this paper will investigate three options for biopower: low co-firing (co-firing scenarios refer to combusting a given percentage of biomass with coal) (5%–10% biomass), medium co-firing (15%–20% biomass), and dedicated biomass firing (100% biomass). We analyze the ...

  12. Comparison of the impact of fire, floods, and large herbivore grazing on the 3-D structure and biomass of Mopane Woodland in Kruger National Park using Terrestrial Laser Scanning

    Science.gov (United States)

    Delgado, A.; Washington-Allen, R. A.; Bruton, R.; Swemmer, A.

    2012-12-01

    We conducted a study to look at the impact of large herbivore grazing exclusion, fire, and flooding on the three dimensional (3-D) structure and biomass of Mopane woodlands using Terrestrial Laser Scanning (TLS). The study was conducted at the 42-ha Letaba exclosure that is located on the northern shore of the Letaba River in the northern part of Kruger National Park (KNP), South Africa. The study entailed comparison of 4 X 30-m diameter paired plots, with 4 treatment (no grazing) plots within the exclosure and 4 control plots outside. Additionally, the northern 4 plots are in upland savanna vegetation on a gravelly loam stream terrace that had been burned in 2010. The southern 4 plots are in riparian woodlands on sandy loam soils that had been flooded in 2007. TLS data was collected at 4-cm spacing with 30-m range at 4 scans per plot. Scans were registered and a 3-D virtual environment was created for each plot from which canopy cover, plant density, and vegetation height were manually measured and biomass was derived. We used discriminant analysis to test the hypothesis that 4 structurally distinct groups would be detected, i.e., burned ungrazed savanna, burned grazed savanna, flooded ungrazed riparian, and a flooded grazed riparian group. We found that point density of grass and trees across plots correlated significantly with plot biomass. We predicted that exclosure biomass would be greater than biomass outside the exclosure and that upland biomass height and density in the canopy, shrub, and herbaceous layers within the exclosure compared to outside. However, though biomass was distinct, structural features were not in the upland pairs.

  13. Utilization of a water-cooled cooking grate. Concept and operating experiences; Einsatz des wassergekuehlten Koch-Rostes. Konzept und Betriebserfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Auel, W.; Kuehl, M. [ThyssenKrupp Xervon Energy GmbH, Duisburg (Germany)

    2007-07-01

    The combustion grate is the key component of a firing system. In the contribution under consideration, the authors report on the utilization of a water-cooled combustion grate in a firing system. The selection criteria for dimensioning a combustion grate as well as the characteristics of the combustion grate system, the concept of the water-cooled grate and operational experiences with the grate system are designated. The small wear of the water-cooled combustion grate results in a remaining distribution of the primary air during the period of operation. The fundamental conditions for an optimized operation of the heating installation and for a long period of operation are given. The firing systems fulfill the firing-conditioned emissions and the quality of burn-out.

  14. History of grating images

    Science.gov (United States)

    Iwata, Fujio

    2001-06-01

    Toppan Printing Co., Ltd. originated the name of 'grating image'. It means an image that consists of diffraction grating dots that look similar to the halftone dots of conventional printing. We proposed this new display method using simple gratings in order to enhance the visual effects when illumination is made by a fluorescent lamp. We considered the use of simple gratings as elemental dots, and used a number of elemental dots to display a 2D image. This method produces an effect something like the halftone dots of printing. The grating image technology grows from its starting to become able to produce 3D images and a 3D-video system using an electron beam grating-writing system.

  15. Grating image technology

    Science.gov (United States)

    Iwata, Fujio

    1995-07-01

    The word 'grating image' was first named by Toppan Printing Company, Ltd. It means that an image consists of grating dots. In 1988, we presented this new technology at the Optical Security Systems Symposium, in Switzerland. Then it was improved and applied in display application. Recently, it was further applied in 3D video systems. In this report, the development history and the recent situations of grating image technology are described.

  16. The effect of cleaning on materials wastage in biomass and waste fired power plants; Sotningens inverkan paa materialfoerluster foer bio- och avfallseldade pannor

    Energy Technology Data Exchange (ETDEWEB)

    Hjoernhede, Anders; Henderson, Pamela

    2006-03-15

    The reason for this study is the relatively large material loss caused by soot blowing of heat exchange surface in waste- and biomass fired boilers. The material losses depend on the method of cleaning: Normally soot blowing with a relatively high pressure is used in order to remove deposits on super heater tubes. However, this also damages the tube material. Earlier theories state that the material losses are caused by erosion or rather erosion-corrosion of the tube surface. There is a clear evidence for the existence for this type of damage, but it is often caused by badly adjusted soot blowing equipment. However, even well adjusted equipment causes accelerated metal loss, albeit lower than with badly adjusted soot blowers. This type of material loss is caused by the removal of the outer molten deposit layer. This outer layer of deposit actually acts as a barrier to corrosive species diffusing inwards towards the oxide and uncorroded metal. There is a lamellar oxide under this deposit, which is especially protective if it contains Cr{sub 2}O{sub 3}, MoO{sub 3} or Nb{sub 2}O{sub 5}. The lamellar oxide is damaged by the defects produced by the soot blowing and the diffusion of corrosive species into the metal tube. Since molybdenum probably through molybdenum oxide seems to reduce metal losses due to soot blowing, alloys containing molybdenum should be used. The addition of sulphur, or sulphur compounds like ammonium sulphate reduces the deposit growth rate by about 50%. This means that the soot blowing frequency and therefore metal losses are reduced. There is also an indication that certain metals or alloys reduce the tendency for deposits to stick to tubes. Coating with pure nickel is one example of this, but as nickel is sensitive to soot blowing it is not possible to use nickel in areas affected by soot blowing. A common way of reducing metal losses is to mount tube shields on the most affected tubes. These shields are changed regularly. Normally expensive

  17. Study into the status of co-combustion of sewage sludge, biomass and household refuse in coal-fired power stations. Final report; Untersuchungen zum Stand der Mitverbrennung von Klaerschlamm, Hausmuell und Biomasse in Kohlekraftwerken. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Spliethoff, H.; Scheurer, W. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen; Seifert, H.; Richers, U. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer technische Chemie - Thermische Abfallbehandlung

    2000-03-01

    The co-combustion of wastes in power stations is an additional option for the thermal treatment of certain waste materials and thus for complying with the specifications of the German TA-Siedlungsabfall (technical directive on disposal of municipal solid waste). The present investigation compiles the status of knowledge about co-combustion of sewage sludge, biomass and selected waste materials in coal-fired power stations. The results are meant to provide extensive assistance to evaluate the processes and thus to contribute to sort out uncertainties, both on the part of power plant operators and of the authorities. Based on the information acquired, the report shall point out the gaps in knowledge, the further need for research and development and the need for action conerning the authorities. By enquiries at disposal enterprises, power station operators as well as authorities, the literature work was completed and a comprehensive view of the current situation in Germany elaborated. The report points out the legal conditions of co-combustion and supplementary fuel potentials, presents the process engineering of co-combustion, and examines the obstacles encountered during the technical conversion, the environmental questions, and the potential for co-combustion of the above materials in existing power stations. The electrical power sector is subject to strong changes due to the liberalisation of the energy market. The pressure on costs has increased and the periods available for planning are shorter. On the one hand, this arouses an increased interest in co-combustion of waste materials because of possible additional payments for the wastes. On the other hand, however, initiatives in this respect are counteracted by high investments costs necessary for the introduction of co-combustion with the existing high environmental standards. What is more, the competitive situation reduces the exchange of experience between the power station operators. Co-combustion of sewage

  18. Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2011-02-01

    Full Text Available Biomass burning emissions factors are vital to quantifying trace gases releases from vegetation fires. Here we evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP, South Africa using ground-based open path Fourier transform infrared (FTIR spectroscopy and an infrared lamp separated by 150–250 m distance. Molecular abundances along the extended open path are retrieved using a spectral forward model coupled to a non-linear least squares fitting approach. We demonstrate derivation of trace gas column amounts for horizontal paths transecting the width of the advected plume, and find, for example, that CO mixing ratio changes of ~0.001 μmol mol−1 (~10 ppbv can be detected across the relatively long optical paths used here. We focus analysis on five key compounds whose production is preferential during the pyrolysis (CH2O, flaming (CO2 and smoldering (CO, CH4, NH3 fire phases. We demonstrate that well constrained emissions ratios for these gases to both CO2 and CO can be derived for the backfire, headfire and residual smouldering combustion stages of these savannah fires, from which stage-specific emission factors can then be calculated. Headfires and backfires in general show similar emission ratios and emission factors, but those of the residual smouldering combustion stage can differ substantially (e.g., ERCH4/CO2 up to ~7 times higher than for the flaming stages. The timing of each fire stage was identified via airborne optical and thermal IR imagery and ground-observer reports, with the airborne IR imagery also used to derive estimates of fire radiative energy, thus allowing the relative amount of fuel burned in each stage to be calculated and the "fire averaged" emission ratios and emission factors to be determined. The derived "fire averaged" emission ratios are dominated by the headfire contribution, since

  19. Materials for higher steam temperatures (up to 600 deg C) in biomass and waste fired plant. A review of present knowledge; Material foer hoegre aangtemperaturer (upp till 600 grader C) i bio- och avfallseldade anlaeggningar

    Energy Technology Data Exchange (ETDEWEB)

    Staalenheim, Annika; Henderson, Pamela

    2011-02-15

    A goal for the Swedish power industry is to build a demonstration biomass-fired plant with 600 deg C steam data in 2015. Vaermeforsk also has a goal to identify materials that can be used in such a plant. This project involves a survey of present knowledge and published articles concerning materials that are suitable for use in biomass and wastefired plants with steam data up to 600 deg C. The information has been gathered from plants presently in operation, and from field tests previously performed with probes. Plants firing only household waste are excluded. The components considered are waterwalls/furnace walls (affected because of higher steam pressures) and superheaters. Fireside corrosion and steam-side oxidation are dealt with. Candidate materials (or coatings) are suggested and areas for further research have been identified. The purpose of this project is to give state-of-the-art information on what materials could be used in biomass and waste-fired plant to reach a maximum steam temperature of 600 deg C. This report is aimed at suppliers of boilers and materials, energy utility companies and others involved in building new plant with higher steam data. In accordance with the goals of this project: - Materials suitable for use at higher steam temperatures (up to 600 deg C steam) in wood-based biomass and waste-fired plant have been identified. Austenitic stainless steels HR3C, TP 347 HFG and AC66 all have adequate strength, steam-side oxidation and fireside corrosion resistance for use as superheaters. AC66 and HR3C have better steam-side oxidation resistance than TP 347 HFG , but TP 347 HFG has better fireside corrosion resistance. It is recommended that TP 347 HFG be shot-peened on the inside to improve the oxidation resistance if in service with steam temperatures above 580 deg C. - Furnace walls coated with Ni-based alloys or a mixture of Ni- alloy and ceramic show good corrosion resistance at lower temperatures and should be evaluated at higher

  20. Nickel- and iron-based HVOF thermal spray coatings for high temperature corrosion protection in biomass-fired power plant boilers

    OpenAIRE

    Oksa, Maria

    2015-01-01

    Biomass burning for production of electricity and heat has been increasing due to legislation in Europe. Growing awareness of environmental problems has led to strict restrictions on greenhouse emissions in the energy sector, and increased demand for higher use of renewable energy sources and carbon-neutral fuels, such as biomass. There are over 1000 biomass boilers in Europe, and the number is increasing. These plants often face serious problems due to high temperature corrosion. Fouling and...

  1. Fiber Bragg grating sensors

    NARCIS (Netherlands)

    Cheng, L.K.; Nieuwland, R.A.; Toet, P.M.; Agovic, K.

    2010-01-01

    A brief overview of fiber Bragg grating based sensor technology from sensor head, read out unit and commercial applications is given. Fiber Bragg grating based sensor systems are becoming mature rapidly. Components for commercial pressure sensors and temperature sensors are available and slowly gett

  2. Bragg gratings in Topas

    DEFF Research Database (Denmark)

    Zhang, C.; Webb, D.J.; Kalli, K.;

    We report for the first time fibre Bragg grating inscription in microstructured optical fibre fabricated from Topas® cyclic olefin copolymer. The temperature sensitivity of the grating was studied revealing a positive Bragg wavelength shift of approximately 0.8 nmK-1,the largest sensitivity yet...

  3. Bidirectional grating compressors

    Science.gov (United States)

    Wang, Cheng; Li, Zhaoyang; Li, Shuai; Liu, Yanqi; Leng, Yuxin; Li, Ruxin

    2016-07-01

    A bidirectional grating compressor for chirped pulse amplifiers is presented. It compresses a laser beam simultaneously in two opposite directions. The pulse compressor is shown to promote chirped pulse amplifiers' output energy without grating damages. To verify the practicability, an experiment is carried out. In addition, a crosscorrelation instrument is designed and set up to test the time synchronization between these two femtosecond pulses.

  4. Fractal Diffraction Grating

    OpenAIRE

    Bak, Dongsu; Kim, Sang Pyo; Kim, Sung Ku; Soh, Kwang-Sup; Yee, Jae Hyung

    1998-01-01

    We consider an optical diffraction grating in which the spatial distribution of open slits forms a fractal set. The Fraunhofer diffraction patterns through the fractal grating are obtained analytically for the simplest triad Cantor type and its generalized version. The resulting interference patterns exhibit characteristics of the original fractals and their scaling properties.

  5. 林火对兴安落叶松根生物量及碳氮养分浓度的影响%Impacts of forest fire on root biomass, carbon and nitrogen concentration of Larix gmelinii

    Institute of Scientific and Technical Information of China (English)

    楚旭; 邸雪颖; 杨光

    2013-01-01

    With Larix gmelinii forests as test objects in Tahe Forestry Bureau on Great Xing'an Mountains, northeastern China, taking the investigation of forests burned at different time, their roots were sampled to analyze the change of root biomass, C and N nutrient concentration and C/N value after the fire. The results showed that: 1 ) One week after fire, live root biomass of low intensity and moderate intensity burning trees were only 80% and 36% of control trees, fine root biomass of < 1 mm diameter were 60% and 19% of control trees, respectively; 2) Three months after fire, fine roots of low intensity burning trees had came to a certain degree of recovery, fine roots of moderate intensity burning trees was significantly lower than the recovery degree of low intensity one. Two years after fire, there was no significant difference between the root biomass of low intensity burning tree and control, and there was no significant difference between fine root biomass of < 1 mm diameter of moderate intensity burning trees and control; 3 ) Fire reduced tree root nutrient concentrations of carbon and nitrogen, low intensity burning decreased the value of C/N, however, moderate intensity burning increased the value of C/N. Forest fire had a significant impact on tree roots. After roots of trees were burned, their physical activity and living environment were also changed and many factors will affect the recovery of roots.%以大兴安岭塔河林业局兴安落叶松林为研究对象,对不同时间火烧迹地进行调查,采用挖掘法获取土壤根系样品,研究火后落叶松根生物量,C、N养分浓度及C/N值变化.结果表明:1)火烧后1周,受低强度和中等强度火烧树木的活根生物量仅是对照树木的80%和36%,<1 mm细根生物量则分别是对照的60%和19%.2)火烧后3个月,受低强度火烧树木细根得到了一定程度的恢复,受中等强度火烧树木根恢复程度明显低于受低强度火烧树木;火后2年,前

  6. Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2011-11-01

    Full Text Available Biomass burning emissions factors are vital to quantifying trace gas release from vegetation fires. Here we evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP, South Africa using ground-based open path Fourier transform infrared (FTIR spectroscopy and an IR source separated by 150–250 m distance. Molecular abundances along the extended open path are retrieved using a spectral forward model coupled to a non-linear least squares fitting approach. We demonstrate derivation of trace gas column amounts for horizontal paths transecting the width of the advected plume, and find for example that CO mixing ratio changes of ~0.01 μmol mol−1 [10 ppbv] can be detected across the relatively long optical paths used here. Though FTIR spectroscopy can detect dozens of different chemical species present in vegetation fire smoke, we focus our analysis on five key combustion products released preferentially during the pyrolysis (CH2O, flaming (CO2 and smoldering (CO, CH4, NH3 processes. We demonstrate that well constrained emissions ratios for these gases to both CO2 and CO can be derived for the backfire, headfire and residual smouldering combustion (RSC stages of these savannah fires, from which stage-specific emission factors can then be calculated. Headfires and backfires often show similar emission ratios and emission factors, but those of the RSC stage can differ substantially. The timing of each fire stage was identified via airborne optical and thermal IR imagery and ground-observer reports, with the airborne IR imagery also used to derive estimates of fire radiative energy (FRE, allowing the relative amount of fuel burned in each stage to be calculated and "fire averaged" emission ratios and emission factors to be determined. These "fire averaged" metrics are dominated by the headfire contribution, since the FRE data indicate that the vast majority

  7. Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

    Science.gov (United States)

    Wooster, M. J.; Freeborn, P. H.; Archibald, S.; Oppenheimer, C.; Roberts, G. J.; Smith, T. E. L.; Govender, N.; Burton, M.; Palumbo, I.

    2011-11-01

    Biomass burning emissions factors are vital to quantifying trace gas release from vegetation fires. Here we evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP), South Africa using ground-based open path Fourier transform infrared (FTIR) spectroscopy and an IR source separated by 150-250 m distance. Molecular abundances along the extended open path are retrieved using a spectral forward model coupled to a non-linear least squares fitting approach. We demonstrate derivation of trace gas column amounts for horizontal paths transecting the width of the advected plume, and find for example that CO mixing ratio changes of ~0.01 μmol mol-1 [10 ppbv] can be detected across the relatively long optical paths used here. Though FTIR spectroscopy can detect dozens of different chemical species present in vegetation fire smoke, we focus our analysis on five key combustion products released preferentially during the pyrolysis (CH2O), flaming (CO2) and smoldering (CO, CH4, NH3) processes. We demonstrate that well constrained emissions ratios for these gases to both CO2 and CO can be derived for the backfire, headfire and residual smouldering combustion (RSC) stages of these savannah fires, from which stage-specific emission factors can then be calculated. Headfires and backfires often show similar emission ratios and emission factors, but those of the RSC stage can differ substantially. The timing of each fire stage was identified via airborne optical and thermal IR imagery and ground-observer reports, with the airborne IR imagery also used to derive estimates of fire radiative energy (FRE), allowing the relative amount of fuel burned in each stage to be calculated and "fire averaged" emission ratios and emission factors to be determined. These "fire averaged" metrics are dominated by the headfire contribution, since the FRE data indicate that the vast majority of the fuel is burned in this stage. Our fire averaged emission ratios and factors

  8. 生物质锅炉与燃煤锅炉颗粒物排放特征比较%Comparative Study on the Particle Emission Characteristics of Biomass Boiler with Coal-Fired Industrial Boiler

    Institute of Scientific and Technical Information of China (English)

    耿春梅; 陈建华; 王歆华; 杨文; 殷宝辉; 刘红杰; 白志鹏

    2013-01-01

    选择2台设计结构不同的生物质锅炉(BB1、BB2),针对木质和秸秆2种生物质燃料开展烟尘、PM10和PM2.5排放特征的研究,并与燃煤锅炉进行比较.结果表明:2台生物质锅炉的大气污染物排放质量浓度都未达到北京市DB 11/139-2007《锅炉大气污染物排放标准》的要求;2台生物质锅炉颗粒物的排放因子存在差别,燃烧木质成型燃料时,BB1和BB2生物质锅炉除尘器后的烟尘排放因子分别为207.10和465.51 mg/kg,PM10排放因子分别为75.18和149.61 mg/kg,PM2.5排放因子分别为58.48和106.86 mg/kg;燃烧秸秆成型燃料时,BB1和BB2生物质锅炉除尘器后的烟尘排放因子分别为142.86和1200.86 mg/kg,PM10排放因子分别为63.63和102.01 mg/kg,PM2.5的排放因子分别为50.90和76.51 mg/kg.与热功率相近的燃煤锅炉比较,2台生物质锅炉除尘器前的PM10平均排放因子低30.41%,PM2.5平均排放因子却高36.84%,即PM2.5在生物质锅炉烟尘中所占比例更高.尽管利用可再生能源的生物质锅炉具有很好的发展前景,但目前该类锅炉仍存在污染物排放不达标的现象,因此,需要提高热能利用效率和除尘效率,以减少污染.%Biomass boilers were widely used as an effective method for biomass combustion.However,there were not many studies on the characteristics of atmospheric pollutants emitted from biomass boilers.Two biomass boilers with different structure were selected to study the emission characteristics of dust,PM10 and PM2.5 and compare it with coal-fired boiler.Wooden block fuel (MZ) and straw block fuel (JG)were used in this study.The results showed that the emission concentrations of pollutants from both biomass boilers could not fulfill Beijing local standard "Emission standard of air pollutants for boilers" (DB 11/139-2007).The emission factors using two types of biomass boilers showed a significant difference.For the wooden block fuel,the dust emission factors were 207.10 mg/kg (BB1

  9. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush; Stephen Niksa

    2003-04-30

    In full-scale boilers, the effect of biomass cofiring on NO{sub x} and unburned carbon (UBC) emissions has been found to be site-specific. Few sets of field data are comparable and no consistent database of information exists upon which cofiring fuel choice or injection system design can be based to assure that NOX emissions will be minimized and UBC be reduced. This report presents the results of a comprehensive project that generated an extensive set of pilot-scale test data that were used to validate a new predictive model for the cofiring of biomass and coal. All testing was performed at the 3.6 MMBtu/hr (1.75 MW{sub t}) Southern Company Services/Southern Research Institute Combustion Research Facility where a variety of burner configurations, coals, biomasses, and biomass injection schemes were utilized to generate a database of consistent, scalable, experimental results (422 separate test conditions). This database was then used to validate a new model for predicting NO{sub x} and UBC emissions from the cofiring of biomass and coal. This model is based on an Advanced Post-Processing (APP) technique that generates an equivalent network of idealized reactor elements from a conventional CFD simulation. The APP reactor network is a computational environment that allows for the incorporation of all relevant chemical reaction mechanisms and provides a new tool to quantify NOx and UBC emissions for any cofired combination of coal and biomass.

  10. Materials for Waste Incinerators and Biomass Plants

    DEFF Research Database (Denmark)

    Rademakers, P.; Grossmann, G.; Karlsson, A.;

    1998-01-01

    This paper reviews the projects of the sub-package on waste incineration and biomass firing carried out within COST 501 Round III, Work Package 13.......This paper reviews the projects of the sub-package on waste incineration and biomass firing carried out within COST 501 Round III, Work Package 13....

  11. Undergraduate Research Experiences in Support of Dryland Monitoring: Field and Satellite Remote Sensing of Change in Savanna Structure, Biomass, and Carbon after Prescribed Fires

    Science.gov (United States)

    Washington-Allen, R. A.; Twidwell, D. L., Jr.; Mendieta, V. P.; Delgado, A.; Redman, B.; Trollope, W. S.; Trollope, L.; Govender, N.; Smit, I.; Popescu, S. C.; de Bruno Austin, C.; Reeves, M. C.

    2009-12-01

    The status and trend of degradation in the world’s Drylands, that support over 1.2 billion people, is unknown because monitoring & assessment has not occurred on a globally consistent basis and skilled personnel with a cultivated interest in natural resource science and management are lacking. A major monitoring dataset is the 37-year Landsat data archive that has been released free to the world, but this dataset requires persons who understand how to process and interpret this and similar datasets applicable to the desertification problem. The College of Agriculture & Life Sciences (COALS) at Texas A&M University (TAMU) has an initiative to provide undergraduates with both international and research experiences. The lead author used start-up money, USFS project funds for livestock footprint studies in the US, and seed money from COALS to 1) develop academic mentor contacts in Mozambique, Namibia, Botswana, South Africa, and Tunisia to prepare a National Science Foundation Research Experience for Undergraduates (NSF-REU) Site proposal and 2) launch a pilot REU for two TAMU undergraduate students. Mr. Delgado and Mr. Redman received lidar processing and visualization, field survey training on global positioning systems (GPS), terrestrial LIDAR, and ground penetrating radar technologies and conducted carbon change studies by collecting pre- and post-fire laser scans on experimental burn (EPB) sites in Texas and South Africa. Mr. Redman also developed GIS databases of Landsat timeseries for these EPBs and others in southern Africa. Mr. Delgado participated in the Savanna Fire Ignition Research Experiment (SavFIRE) in Kruger National Park (KNP) by collected laser scan data on 3 EPBs. He also received mentoring from Dr. Winston Trollope, a prominent fire ecologist, and Mr. Chris Austin both of Working with Fire International and Navashni Govender, KNP’s Fire Ecologist. He also was an active participant in a NASA sponsored workshop on remote sensing of global

  12. deNOx catalysts for biomass combustion

    OpenAIRE

    Kristensen, Steffen Buus; Riisager, Anders; Fehrmann, Rasmus; Nørklit Jensen, Jørgen

    2013-01-01

    The present thesis revolves around the challenges involved in removal of nitrogen oxides in biomass fired power plants. Nitrogen oxides are unwanted byproducts formed to some extent during almost any combustion. In coal fired plants these byproducts are removed by selective catalytic reduction, however the alkali in biomass complicate matters. Alkali in biomass severely deactivates the catalyst used for the selective catalytic reduction in matter of weeks,hence a more alkali resistant catalys...

  13. Fire Perimeters

    Data.gov (United States)

    California Department of Resources — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2003. Some fires...

  14. Fire History

    Data.gov (United States)

    California Department of Resources — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2002. Some fires...

  15. Tutorial: Applications of Fibre Gratings

    Institute of Scientific and Technical Information of China (English)

    Hwayaw; Tam; Bai; ou; Guan; Shunyee; Liu

    2003-01-01

    Fibre grating is an important enabling technology that has found numerous applications in both telecommunications and sensor systems. This tutorial describes the basic characteristics of fibre gratings and gives examples of where they are being employed.

  16. Integral Method for Gratings

    CERN Document Server

    Maystre, Daniel

    2014-01-01

    The chapter contains a detailed presentation of the surface integral theory for modelling light diffraction by surface-relief diffraction gratings having a one-dimensional periodicity. Several different approaches are presented, leading either to a single integral equation, or to a system of coupled integral equations. Special attention is paid to the singularities of the kernels, and to different techniques to accelerate the convergence of the numerical computations. The theory is applied to gratings having different profiles with or without edges, to real metal and dielectrics, and to perfectly conducting substrates.

  17. Ultra-High Temperature Gratings

    Institute of Scientific and Technical Information of China (English)

    John Canning; Somnath Bandyopadhyay; Michael Stevenson; Kevin Cook

    2008-01-01

    Regenerated gratings seeded by type-Ⅰ gratings are shown to withstand temperatures beyond 1000 ℃. The method of regeneration offers a new approach to increasing temperature resistance of stable fibre Bragg and other gratings. These ultra-high temperature (UHT) gratings extend the applicability of silicate based components to high temperature applications such as monitoring of smelters and vehicle and aircraft engines to high power fibre lasers.

  18. 生物质燃料锅炉20G钢低温过热器管爆裂失效分析%Burst failure analysis on 20G steel low temperature superheater tube of biomass-fired boiler

    Institute of Scientific and Technical Information of China (English)

    卿辉; 任耀剑; 孙智

    2014-01-01

    Reason for the failure of low temperature superheater tube of biomass-fired boiler during working was analyzed .The results show that the tube burst is related to the ash of biomass fuel and many short-terms over-high temperature .The alkali chloride and sulfide of the ash of biomass fuel accelerated corrosion and oxides generated , and the tube undergone short-term over-temperature repeatedly .Over-temperature caused pearlitic spheroidization and decreased strength of the material in the meantime .The tube cracking was due to the tube wall thinned by oxide abscission , and could not resist the boiler pressure .%某生物质燃料锅炉低温过热器管在运行中爆裂,对其失效原因进行了分析。结果表明,爆管的原因与生物质燃料灰分和多次短时超温有关。燃料灰分中的碱金属氯化物、硫化物使腐蚀加速,形成氧化物的速度加快,并使管道经历多次短时超温。超温造成组织中珠光体球化,使材料强度下降。氧化物脱落后,管壁的实际壁厚减薄,不足以承受管中的压力导致爆裂。

  19. The formation of aerosol particles during combustion of biomass and waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hjerrild Zeuthen, J.

    2007-05-15

    This thesis describes the formation of aerosol particles during combustion of biomass and waste. The formation of aerosol particles is investigated by studying condensation of alkali salts from synthetic flue gasses in a laboratory tubular furnace. In this so-called laminar flow aerosol condenser-furnace gaseous alkali chlorides are mixed with sulphur dioxide, water vapour and oxygen. At high temperatures the alkali chloride reacts with sulphur dioxide to form alkali sulphate. During subsequent cooling of the synthetic flue gas the chlorides and sulphates condense either as deposits on walls or on other particles or directly from the gas phase by homogenous nucleation. A previously developed computer code for simulation of one-component nucleation of particles in a cylindrical laminar flow is extended to include a homogeneous gas phase reaction to produce gaseous alkali sulphate. The formation of aerosol particles during full-scale combustion of wheat straw is investigated in a 100 MW grate-fired boiler. Finally, aerosols from incineration of waste are investigated during full-scale combustion of municipal waste in a 22 MW grate-fired unit. (BA)

  20. Bragg grating rogue wave

    CERN Document Server

    Degasperis, Antonio; Aceves, Alejandro B

    2015-01-01

    We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing, may lead to extreme waves at extremely low powers.

  1. Bragg grating rogue wave

    Energy Technology Data Exchange (ETDEWEB)

    Degasperis, Antonio [Dipartimento di Fisica, “Sapienza” Università di Roma, P.le A. Moro 2, 00185 Roma (Italy); Wabnitz, Stefan, E-mail: stefan.wabnitz@unibs.it [Dipartimento di Ingegneria dell' Informazione, Università degli Studi di Brescia and INO-CNR, via Branze 38, 25123 Brescia (Italy); Aceves, Alejandro B. [Southern Methodist University, Dallas (United States)

    2015-06-12

    We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing may lead to extreme waves at extremely low powers.

  2. 2D and 3D Eulerian Simulations of the Dynamics and Gas and Aerosol Chemistry of a Young Biomass Burning Smoke Plume from a Savannah Fire

    Science.gov (United States)

    Alvarado, M. J.; Prinn, R. G.

    2007-12-01

    The growth of aerosol particles and production of ozone in young smoke plumes is the result of a complex interaction between the mean flow in the smoke plume, turbulent diffusion, gas-phase oxidation, coagulation, and mass transfer between phases. Models allow us to separate the effects of these processes and predict their impact on the global environment. We present the results of two and three-dimensional Eulerian simulations of the dynamics and chemistry of the smoke plume formed by the Timbavati savannah fire studied during SAFARI 2000 (Hobbs et al., 2003, JGR, doi:10.1029/2002JD002352). The dynamical model is an extension of an Eulerian cloud-resolving model that has previously been used to study the role of deep convective clouds on tropospheric chemistry (Wang and Prinn, 2000, JGR, 105(D17) 22,269-22,297). The model includes a source of sensible heat, gases, and particles at the surface to simulate the savannah fire. The new gas and aerosol chemistry model includes heterogeneous chemistry, kinetic mass transfer, coagulation and the formation of secondary organic and inorganic aerosol. Photolysis rates are calculated based on the solution of the radiative transfer equation within the plume, including the scattering and absorption of radiation by the smoke aerosols. Our preliminary 2D Eulerian results using standard chemistry and UV fluxes show that the model can simulate the lower but not the higher levels of O3 observed. Also, the simulated 2D O3 field shows a wave-like pattern in the downwind direction, even though the emissions from the fire are held constant. This suggests that plume heterogeneity in the downwind direction may account for some of the observed variability in O3. We will present results of runs incorporating higher resolution calculation of photolysis rates, heterogeneous HONO formation, and gas phase reactions involving the uncharacterized organic compounds observed in the gas phase of the Timbavati plume in order to better simulate these

  3. Microscale modelling of ambient air concentrations resulting from the increased combustion of biomass firing systems within the 1{sup st} Ordinance for the Implementation of the Federal Immission Control Act (1. BImSchV); Modellrechnungen zu den Immissionsbelastungen bei einer verstaerkten Verfeuerung von Biomasse in Feuerungsanlagen der 1. BImSchV

    Energy Technology Data Exchange (ETDEWEB)

    Baumbach, Guenter; Struschka, Michael; Juschka, Winfried; Carrasco, Maria; Ang, Keng Been; Hu, Lupin [Stuttgart Univ. (DE). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD); Baechlin, Wolfgang; Soergel, Christine [Ingenieurbuero Lohmeyer GmbH und Co. KG, Karlsruhe (Germany)

    2010-06-15

    By means of a detailed emissions modelling with subsequent highly resolved ambient air pollutant dispersion modelling an assessment method has been developed. This method is a tool for city planners to assess the effects of an increased usage of biomass in heating firings on the air quality situation in different residential areas. Emission simulations have been carried out for the combustion of wood pellets, log wood, wood chips and grain residues as well as for natural gas and heating oil. The emissions depend on the ambient temperature, the building and user specific heat demand and on the operation conditions of the firing. For the operation conditions different emission factors have been set for nominal and partial load as well as for unsteady conditions like boiler start or for shutdown of the firing. The following firings have been considered for burning the above mentioned fuels: Central heating boilers, decentralised heating networks with pellet and wood chip boilers, single stoves for additional heating and grain residue furnaces. Dependent on the ambient temperature for different regions of Germany and for a reference year of the Deutsche Wetterdienst annual emission time series with 1h resolution have been calculated for the different firing fuel combinations. Using these modelled emission data dispersion modelling was carried out for different meteorological and building specific frame conditions. A rural and an urban model area have been investigated. The emissions time series which were calculated for the individual buildings with 1h time resolution were spatially allocated and each single chimney was simulated as point source. For modelling the flow field coined by the building structure the flow model MISKAM has been applied. For dispersion simulation the model AUSTAL2000 has been used. Simulations have been carried out with three different wind and dispersion class distributions typical for many regions of Germany. A further parameter variation

  4. Transfer characteristics of heavy metals under biomass waste and plastics waste co-firing conditions%生物质与塑料类垃圾混烧过程的重金属迁移特性

    Institute of Scientific and Technical Information of China (English)

    谢明超; 马晓茜; 曾广博

    2015-01-01

    To study the weight loss rate and transfer behavior of heavy metals (Pb,Cu,Zn)under biomass wastes and plastic wastes co-firing conditions,experiments about seven components (wood,paper,rubber,recycled PE,re-cycled PP,recycled PS and recycled PVC)were conducted on a tube furnace and a atomic absorption spectropho-tometer.The results show that,co-combustion of biomass and plastic wastes causes a decrease in weight loss rate of the samples,especially the paper.When the sample is burned alone,the volatilization rate of Pb can reach over 85%at 900 ℃,that of Cu in four plastic wastes can reach over 85% at 1 000 ℃,and that of Zn rises significantly at high temperatures.Pb can be captured in bottom ash when the paper is co-fired with the plastics except the PVC.Cu can be captured in bottom ash when the wood and paper are co-fired with the PVC and the rubber.Zn can be captured in bottom ash when the wood is co-fired with the plastics except the rubber or the paper with the PS.%为了研究生物质与塑料类垃圾混烧对失重率和重金属 Pb,Cu,Zn 迁移特性的影响,利用管式炉和原子吸收分光光度计对木、纸、橡胶、再生 PE、再生 PP、再生 PS 和再生 PVC 7种组分进行燃烧试验。结果表明:1)生物质与塑料类垃圾混烧会不同程度地降低样品失重率,纸比木降幅更明显;2)单样燃烧时,900℃下 Pb 的挥发率可达85%以上,1000℃下4种塑料中 Cu的挥发率可达85%以上,高温阶段 Zn 的挥发率明显上升;3)纸与除 PVC 外的塑料混烧可以使 Pb 固定在底灰中;4)木、纸分别与 PVC 和橡胶混烧,可以使 Cu 固定在底灰中;5)木与除橡胶外的塑料混烧、纸与 PS 混烧,均可使 Zn 固定在底灰中。

  5. Temperature effects in concrete structures measured with fibre Bragg grating

    Science.gov (United States)

    Silva, Jean C.; Martelli, Cicero; Penner, Elisabeth; Kalinowski, Hypolito J.

    2004-06-01

    We analyze the action of fire, causing degradation in a concrete cantilever beam using dynamic testing. The structure is instrumented with two fiber Bragg gratings (FBG) sensors. One of them is used to measure vibration and another one is used to measure temperature inside of the cantilever beam, while the beam is exposed to fire. The temperature in the cantilever beam increased until 150°C and a reduction in the strength of concrete can be observed through the modal analysis. A fiber Bragg grating interrogation system, based on tunable filter method, is used for the static and dynamic measurements during the experiments. That system has low cost and it is easy to assemble and maintain when compared to other available instruments.

  6. Growth characteristics of biomass-fired PM2. 5 with vapor condensation%生物质燃烧源PM2.5在水汽条件下长大特性的研究

    Institute of Scientific and Technical Information of China (English)

    徐俊超; 于燕; 张军; 孟强; 钟辉; 尹艳山

    2016-01-01

    The growth characteristic of biomass-fired PM2. 5 with vapor condensation was studied. A growth tube was employed to investigate the growth performance of PM2. 5 at various temperatures of water, initial concentrations of particles, residence times and surfactants. The results show that the growth performance of PM2. 5 from biomass combustion is better than that of coal-fired PM2. 5 with vapor condensation. Furthermore, both the water temperature increase and the residence time delay benefit the growth of PM2. 5 . Unlike the growth of PM2. 5 from coal combustion, the growth of small size of particles is seldom affected by the initial particles concentration. However, with a certain amount of surfactant addition, the particles can all grow up to 1μm .%研究了生物质燃烧源产生的细颗粒在水汽条件下的长大特性,通过生长管实验研究了不同的热水温度、颗粒初始浓度、颗粒在生长管中的停留时间及表面活性剂下生物质燃烧源细颗粒在水汽过饱和条件中的长大特性。与燃煤细颗粒在水汽条件下的长大结果进行对比,生物质燃烧源细颗粒的长大效果要比燃煤细颗粒长大效果要好,热水温度的升高、停留时间的延长有利于细颗粒的长大,小粒径段颗粒的长大则几乎不受颗粒初始浓度的影响,添加一定量的表面活性剂可以使得生物质燃烧源细颗粒全部长大至1μm以上。

  7. Romania biomass energy. Country study

    International Nuclear Information System (INIS)

    The present report was prepared under contract to UNIDO to conduct a case study of biomass energy use and potential in Romania. The purpose of the case study is to provide a specific example of biomass energy issues and potential in the context of the economic transition under way in eastern Europe. The transition of Romania to a market economy is proceeding at a somewhat slower pace than in other countries of eastern Europe. Unfortunately, the former regime forced the use of biomass energy with inadequate technology and infrastructure, particularly in rural areas. The resulting poor performance thus severely damaged the reputation of biomass energy in Romania as a viable, reliable resource. Today, efforts to rejuvenate biomass energy and tap into its multiple benefits are proving challenging. Several sound biomass energy development strategies were identified through the case study, on the basis of estimates of availability and current use of biomass resources; suggestions for enhancing potential biomass energy resources; an overview of appropriate conversion technologies and markets for biomass in Romania; and estimates of the economic and environmental impacts of the utilization of biomass energy. Finally, optimal strategies for near-, medium- and long-term biomass energy development, as well as observations and recommendations concerning policy, legislative and institutional issues affecting the development of biomass energy in Romania are presented. The most promising near-term biomass energy options include the use of biomass in district heating systems; cofiring of biomass in existing coal-fired power plants or combined heat and power plants; and using co-generation systems in thriving industries to optimize the efficient use of biomass resources. Mid-term and long-term opportunities include improving the efficiency of wood stoves used for cooking and heating in rural areas; repairing the reputation of biogasification to take advantage of livestock wastes

  8. Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J. [Foster Wheeler Energia Oy, Varkaus (Finland). Varkaus Global New Products

    1997-12-31

    Laempoevoima Oy`s Kymijaervi power plant gasification project is to demonstrate the direct gasification of wet biofuel and the use of hot, raw and very low-calorific gas directly in the existing coal-fired boiler. The gasification of biofuels and co-combustion of gases in the existing coal-fired boiler offers many advantages such as: recycling of CO{sub 2}, decreased SO{sub 2} and NO{sub x} emissions, efficient way to utilize biofuels and recycled refuse fuels, low investment and operation costs, and utilization of the existing power plant capacity. Furthermore, only small modifications are required in the boiler, possible disturbances in the gasifier do not shut down the power plant. (author)

  9. Development of METHANE de-NOX Reburn Process for Wood Waste and Biomass Fired Stoker Boilers - Final Report - METHANE de-NOX Reburn Technology Manual

    Energy Technology Data Exchange (ETDEWEB)

    J. Rabovitser; B. Bryan; S. Wohadlo; S. Nester; J. Vaught; M. Tartan (Gas Technology Institute); R. Glickert (ESA Environmental Solutions)

    2007-12-31

    The overall objective of this project was to demonstrate the effectiveness of the METHANE de-NOX® (MdN) Reburn process in the Forest Products Industry (FPI) to provide more efficient use of wood and sludge waste (biosolids) combustion for both energy generation and emissions reduction (specifically from nitrogen oxides (NOx)) and to promote the transfer of the technology to the wide range of wood waste-fired stoker boilers populating the FPI. This document, MdN Reburn Commercial Technology Manual, was prepared to be a resource to promote technology transfer and commercialization activities of MdN in the industry and to assist potential users understand its application and installation requirements. The Manual includes a compilation of MdN commercial design data from four different stoker boiler designs that were baseline tested as part of the development effort. Design information in the Manual include boiler CFD model studies, process design protocols, engineering data sheets and commercial installation drawings. Each design package is unique and implemented in a manner to meet specific mill requirements.

  10. Biomass boilers

    OpenAIRE

    Nahodil, Jiří

    2011-01-01

    Bachelor’s thesis deals with the use of biomass for heating houses and apartment houses. The first part is dedicated to biomass. Here are mentioned the possibility of energy recovery, treatment and transformation of biomass into a form suitable for burning, its properties and combustion process itself. The second part is devoted to biomass boilers, their separation and description. The last section compares the specific biomass boiler with a boiler to natural gas, particularly from an economi...

  11. Characterization of pinhole transmission gratings.

    Science.gov (United States)

    Eidmann, K; Kühne, M; Müller, P; Tsakiris, G D

    1990-01-01

    Gold pinhole transmission gratings fabricated by Heidenhain GmbH primarily for the purpose of studying the radiation of intense soft x-ray sources have been tested with the synchrotron radiation of BESSY. Typical results for the spectral dependence of the grating efficiency into the various diffraction orders are presented in a wavelength region ranging from 4 to 20 nm. Also the influence of grating irregularities has been studied. With appropriate grating parameters quite good agreement between the experimental results and theoretical Calculations is Obtained. PMID:21307429

  12. Improved biomass Injera stove- Mirte

    International Nuclear Information System (INIS)

    The status report of 1994 - 1995 shows as the need to design an improved biomass stove for Injera was recognized. The marketing began in mid-1994 with a Mirte which showed even higher efficiencies in laboratory, using 50 percent less woody biomass than the open fire. By early 1994 several hundreds Mirte stoves had been sold in Addis Ababa at non-subsidized prices. The Mirte is currently produced on a large-scale by building materials companies. 3 figs. 1 tab

  13. The Use of Aerosol Optical Depth in Estimating Trace Gas Emissions from Biomass Burning Plumes

    Science.gov (United States)

    Jones, N.; Paton-Walsh, C.; Wilson, S.; Meier, A.; Deutscher, N.; Griffith, D.; Murcray, F.

    2003-12-01

    We have observed significant correlations between aerosol optical depth (AOD) at 500 nm and column amounts of a number of biomass burning indicators (carbon monoxide, hydrogen cyanide, formaldehyde and ammonia) in bushfire smoke plumes over SE Australia during the 2001/2002 and 2002/2003 fire seasons from remote sensing measurements. The Department of Chemistry, University of Wollongong, operates a high resolution Fourier Transform Spectrometer (FTS), in the city of Wollongong, approximately 80 km south of Sydney. During the recent bushfires we collected over 1500 solar FTIR spectra directly through the smoke over Wollongong. The total column amounts of the biomass burning indicators were calculated using the profile retrieval software package SFIT2. Using the same solar beam, a small grating spectrometer equipped with a 2048 pixel CCD detector array, was used to calculate simultaneous aerosol optical depths. This dataset is therefore unique in its temporal sampling, location to active fires, and range of simultaneously measured constituents. There are several important applications of the AOD to gas column correlation. The estimation of global emissions from biomass burning currently has very large associated uncertainties. The use of visible radiances measured by satellites, and hence AOD, could significantly reduce these uncertainties by giving a direct estimate of global emissions of gases from biomass burning through application of the AOD to gas correlation. On a more local level, satellite-derived aerosol optical depth maps could be inverted to infer approximate concentration levels of smoke-related pollutants at the ground and in the lower troposphere, and thus can be used to determine the nature of any significant health impacts.

  14. Supersymmetric Bragg gratings

    CERN Document Server

    Longhi, Stefano

    2015-01-01

    The supersymmetric (SUSY) structure of coupled-mode equations that describe scattering of optical waves in one-dimensional Bragg gratings is highlighted. This property can find applications to the synthesis of special Bragg filters and distributed-feedback (DFB) optical cavities. In particular, multiple SUSY (Darboux-Crum) transformations can be used to synthesize DFB filters with any desired number of resonances at target frequencies. As an example, we describe the design of a DFB structure with a set of equally-spaced resonances, i.e. a frequency comb transmission filter.

  15. Supersymmetric Bragg gratings

    International Nuclear Information System (INIS)

    The supersymmetric (SUSY) structure of coupled-mode equations that describe scattering of optical waves in one-dimensional Bragg gratings is highlighted. This property can find applications to the synthesis of special Bragg filters and distributed-feedback (DFB) optical cavities. In particular, multiple SUSY (Darboux–Crum) transformations can be used to synthesize DFB filters with any desired number of resonances at target frequencies. As an example, we describe the design of a DFB structure with a set of equally-spaced resonances, i.e. a frequency comb transmission filter. (paper)

  16. Developing Engineered Fuel (Briquettes) Using Fly Ash from the Aquila Coal-Fired Power Plant in Canon City and Locally Available Biomass Waste

    Energy Technology Data Exchange (ETDEWEB)

    H. Carrasco; H. Sarper

    2006-06-30

    The objective of this research is to explore the feasibility of producing engineered fuels from a combination of renewable and non renewable energy sources. The components are flyash (containing coal fines) and locally available biomass waste. The constraints were such that no other binder additives were to be added. Listed below are the main accomplishments of the project: (1) Determination of the carbon content of the flyash sample from the Aquila plant. It was found to be around 43%. (2) Experiments were carried out using a model which simulates the press process of a wood pellet machine, i.e. a bench press machine with a close chamber, to find out the ideal ratio of wood and fly ash to be mixed to get the desired briquette. The ideal ratio was found to have 60% wood and 40% flyash. (3) The moisture content required to produce the briquettes was found to be anything below 5.8%. (4) The most suitable pressure required to extract the lignin form the wood and cause the binding of the mixture was determined to be 3000psi. At this pressure, the briquettes withstood an average of 150psi on its lateral side. (5) An energy content analysis was performed and the BTU content was determined to be approximately 8912 BTU/lb. (6) The environmental analysis was carried out and no abnormalities were noted. (7) Industrial visits were made to pellet manufacturing plants to investigate the most suitable manufacturing process for the briquettes. (8) A simulation model of extrusion process was developed to explore the possibility of using a cattle feed plant operating on extrusion process to produce briquettes. (9) Attempt to produce 2 tons of briquettes was not successful. The research team conducted a trial production run at a Feed Mill in La Junta, CO to produce two (2) tons of briquettes using the extrusion process in place. The goal was to, immediately after producing the briquettes; send them through Aquila's current system to test the ability of the briquettes to flow

  17. Emission characteristics of anthracite co-fired with biomass%无烟煤掺烧生物质燃烧产物排放特性

    Institute of Scientific and Technical Information of China (English)

    张超; 鲁光武

    2014-01-01

    为了研究无烟煤掺烧生物质燃烧产物的排放特性,应用卧式单脚炉燃烧试验系统对燃烧产物排放特性进行了研究,分析了炉温、混合比例等参数对污染物排放特性的影响.结果表明:全木屑燃烧速度最快,火焰最高温度位置提前;增加木屑掺烧比例,可以促进混合燃料的着火,但会使炉膛整体燃烧温度降低;当过量空气系数由1.2降至0.9且煤与木屑掺烧比例为9∶1时,炉膛整体燃烧温度上升,火焰高温区靠近燃烧器附近;混合燃料易燃性增强,降低了燃烧中的CO含量;木屑的加入使燃料燃烧特性增强,氧气耗量增大,从而会形成弱还原气氛,有助于降低燃烧中N Ox 的生成.%The horizontal single foot furnace combustion test system was employed to carry out emission characteristics study on combustion and co-combustion of biomass and anthracite.The effect of furnace temperature and mixing ratio on emissions characteristics was investigated.The results show that:the wood had the fastest burning rate,its peak flame temperature moved in advance;increasing the sawdust proportion can promote ignition of the mixture but reduce the overall combustion temperature;when the excess air coefficient decreased from 1.2 to 0.9,the overall combustion temperature increased and the flame temperature zone moved in advance.The flammability of the mixed fuel enhanced,which reduced the CO content during combustion;addition of the sawdust enhanced the combustion,consumed a large amount of oxygen,thus to form a weak reducing atmosphere to help reduce the formation of NOx.

  18. Picosecond Holographic-Grating Spectroscopy

    NARCIS (Netherlands)

    Duppen, K.

    1987-01-01

    Interfering light waves produce an optical interference pattern in any medium that interacts with light. This modulation of some physical parameter of the system acts as a classical holographic grating for optical radiation. When such a grating is produced through interaction of pulsed light waves w

  19. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    sampled gratings, was produced and investigated. It is based on the different temperature and strain response of these gratings. Both a transfer matrix method and an overlap calculation is performed to explain the sensor response. Another type of sensor is based on tuning and modulation of a laser...

  20. Stretchable diffraction gratings for spectrometry

    NARCIS (Netherlands)

    Simonov, A.N.; Grabarnik, S.; Vdovine, G.V

    2007-01-01

    We have investigated the possibility of using transparent stretchable diffraction gratings for spectrometric applications. The gratings were fabricated by replication of a triangular-groove master into a transparent viscoelastic. The sample length, and hence the spatial period, can be reversibly cha

  1. Boiler conversions for biomass

    Energy Technology Data Exchange (ETDEWEB)

    Kinni, J. [Tampella Power Inc., Tampere (Finland)

    1996-12-31

    Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

  2. Biomass combustion gas turbine CHP

    Energy Technology Data Exchange (ETDEWEB)

    Pritchard, D.

    2002-07-01

    This report summarises the results of a project to develop a small scale biomass combustor generating system using a biomass combustor and a micro-gas turbine indirectly fired via a high temperature heat exchanger. Details are given of the specification of commercially available micro-turbines, the manufacture of a biomass converter, the development of a mathematical model to predict the compatibility of the combustor and the heat exchanger with various compressors and turbines, and the utilisation of waste heat for the turbine exhaust.

  3. Process monitor gratings

    Science.gov (United States)

    Brunner, T. A.; Ausschnitt, C. P.

    2007-03-01

    Despite the increasing use of advanced imaging methods to pattern chip features, process windows continue to shrink with decreasing critical dimensions. Controlling the manufacturing process within these shrinking windows requires monitor structures designed to maximize both sensitivity and robustness. In particular, monitor structures must exhibit a large, measurable response to dose and focus changes over the entire range of the critical features process window. Any process variations present fundamental challenges to the effectiveness of OPC methods, since the shape compensation assumes a repeatable process. One particular process parameter which is under increasing scrutiny is focus blur, e.g. from finite laser bandwidth, which can cause such OPC instability, and thereby damage pattern fidelity. We introduce a new type of test target called the Process Monitor Grating (PMG) which is designed for extreme sensitivity to process variation. The PMG design principle is to use assist features to zero out higher diffraction orders. We show via simulation and experiment that such structures are indeed very sensitive to process variation. In addition, PMG targets have other desirable attributes such as mask manufacturability, robustness to pattern collapse, and compatibility with standard CD metrology methods such as scatterometry. PMG targets are applicable to the accurate determination of dose and focus deviations, and in combination with an isofocal grating target, allow the accurate determination of focus blur. The methods shown in this paper are broadly applicable to the characterization of process deviations using test wafers or to the control of product using kerf structures.

  4. 生物质气化火灾爆炸事故复合型风险评价%Integrated Risk Assessment of Biomass Gasified Fire and Explosion Accidents

    Institute of Scientific and Technical Information of China (English)

    闫放; 许开立; 姚锡文; 王犇

    2015-01-01

    为降低生物质气化火灾爆炸事故发生的概率,提出了一种将贝叶斯网络与 boW-tie 法相结合的风险评价方法。通过建立火灾爆炸事故的故障树并转化成贝叶斯网络,然后计算各基本事件的重要度,进而找出系统中导致事故发生的薄弱环节。采用 boW-tie 对薄弱环节进行分析,提出相应的预防措施与控制措施,并计算了薄弱环节采取控制措施后事故发生概率降低的幅度。该方法可精确找出导致事故发生的最主要原因及有效预防控制措施,达到有效降低生物质气化火灾爆炸事故发生概率的目的。%In order to reduce the occurrence of fire and explosion accidents ,a risk assessment approach integrating Bayesian netWork and boW-tie analysis Was proposed.Firstly,the fault tree is established and transformed into Bayesian netWork.Then the Weak points Which might lead to accidents can be pinpointed by calculating the importance of each basic event.The boW-tie analysis is given on the Weak points to Work out the precautions and control measures,and the reduction of accident frequency is calculated after taking control measures for the Weak points. The reasons for such accidents can be found accurately by this approach,Which helps to take appropriate precautions and control measures so as to effectively reduce the occurrence of biomass gasified fire and explosion accidents.

  5. Biomass pretreatment

    Science.gov (United States)

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  6. The role of semi-volatile organic compounds in the mesoscale evolution of biomass burning aerosol: a modeling case study of the 2010 mega-fire event in Russia

    Science.gov (United States)

    Konovalov, I. B.; Beekmann, M.; Berezin, E. V.; Petetin, H.; Mielonen, T.; Kuznetsova, I. N.; Andreae, M. O.

    2015-12-01

    Chemistry transport models (CTMs) are an indispensable tool for studying and predicting atmospheric and climate effects associated with carbonaceous aerosol from open biomass burning (BB); this type of aerosol is known to contribute significantly to both global radiative forcing and to episodes of air pollution in regions affected by wildfires. Improving model performance requires systematic comparison of simulation results with measurements of BB aerosol and elucidation of possible reasons for discrepancies between them, which, by default, are frequently attributed in the literature to uncertainties in emission data. Based on published laboratory data on the atmospheric evolution of BB aerosol and using the volatility basis set (VBS) framework for organic aerosol modeling, we examined the importance of taking gas-particle partitioning and oxidation of semi-volatile organic compounds (SVOCs) into account in simulations of the mesoscale evolution of smoke plumes from intense wildfires that occurred in western Russia in 2010. Biomass burning emissions of primary aerosol components were constrained with PM10 and CO data from the air pollution monitoring network in the Moscow region. The results of the simulations performed with the CHIMERE CTM were evaluated by considering, in particular, the ratio of smoke-related enhancements in PM10 and CO concentrations (ΔPM10 and ΔCO) measured in Finland (in the city of Kuopio), nearly 1000 km downstream of the fire emission sources. It is found that while the simulations based on a "conventional" approach to BB aerosol modeling (disregarding oxidation of SVOCs and assuming organic aerosol material to be non-volatile) strongly underestimated values of ΔPM10/ΔCO observed in Kuopio (by a factor of 2), employing the "advanced" representation of atmospheric processing of organic aerosol material resulted in bringing the simulations to a much closer agreement with the ground measurements. Furthermore, taking gas

  7. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    for the indirectly fired gas turbine (IFGT) and for the supplementary-fired IFGT. These results show that the combination of external firing and internal firing have the potential of reducing or solving some problems associated with the use of biomass both in the recuperated and the indirectly fired gas turbine......This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supple-mentary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, sup-plementary firing is expected...... to result in a high marginal efficiency. The paper shows that depending on the application, this is not always the case. The interest in this cycle arises from a recent demonstration of the feasibility of a two-stage gasification process through construction of several plants. The gas from this process...

  8. Experimental Investigation on Addition of Anticorrosive Agent in a 50-MW Biomass-Fired Circulating Fluidized Bed Boiler%生物质循环流化床锅炉掺烧防腐蚀剂的试验研究

    Institute of Scientific and Technical Information of China (English)

    宋景慧; 谭巍

    2014-01-01

    Experiments on combustion of pure biomass and biomass with anticorrosive agent were carried out in a 50-MW biomass-fired circulating fluidized bed boiler. The anticorrosive agent has a porous structure and mainly contains magnesium oxide (MgO), kaolin, activated alumina (Al2O3) and foamer. Results obtained in experiments show that, boiler thermal efficiency was weakly influenced by the anticorrosive agent, and contents of K and Cl in flue ash decreased as contrast to the increase of K and Cl in furnace slag. When the mass percentage of anticorrosive agent is 3%, in the flue ash, the K values ranged from 7.62%to 5.69%, and Cl values reduced from 3.86%to 2.35%. While in furnace slag, the values K varied from 4.03%to 4.71%, and Cl values increased from 756.58 mg/kg to 1 121.31 mg/kg. Due to the anticorrosive agent, the content of HCl in flue gas decreased from 25 mg/Nm3 to 15 mg/Nm3, as the emission of NO increased from 268 mg/Nm3 to 309 mg/Nm3.%在亚洲最大的50 MW生物质循环流化床直燃锅炉上进行了掺烧防腐蚀剂的燃烧试验,防腐蚀剂采用多孔膜结构,主要成分是MgO、高岭土、活性Al2O3和发泡剂,试验结果表明:掺烧防腐蚀剂不会降低锅炉热效率,且能够有效地降低飞灰中K、Cl元素的含量,将其固留在炉渣中。当防腐蚀剂添加量占总燃料质量的3%时,飞灰中的K元素含量由7.62%下降为5.69%,Cl元素含量由3.86%下降为2.35%;而炉渣中的K元素含量由4.03%上升为4.71%,Cl元素含量由756.58 mg/kg上升为1121.31 mg/kg;同时烟气中的HCl排放量由25 mg/Nm3下降为15 mg/Nm3,NO含量由268 mg/Nm3上升为309 mg/Nm3。

  9. CFD simulation of coal and straw co-firing

    DEFF Research Database (Denmark)

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

    This paper presents the results of a major R&D program with the objective to develop CFD based tools to assess the impact of biomass co-firing in suspension fired pulverized coal power plants. The models have been developed through a series of Danish research projects with the overall objective...... emissions. Results are presented for a Danish full-scale boiler that is currently co-firing biomass with coal on a commercial basis....

  10. Extreme Silica Optical Fibre Gratings

    Directory of Open Access Journals (Sweden)

    Kevin Cook

    2008-10-01

    Full Text Available A regenerated optical fibre Bragg grating that survives temperature cycling up to 1,295°C is demonstrated. A model based on seeded crystallisation or amorphisation is proposed.

  11. New developments and applications of the Steinmueller mass burn grate system

    Energy Technology Data Exchange (ETDEWEB)

    Lux, P.; Hartenstein, H.U.; Licata, A.

    1998-07-01

    The L. and C. Steinmuller GmbH (LCS) mass burn grate system has been extensively used in numerous mass burn waterwall waste-to-energy (WTE) facilities around the world. Among those are three WTE plants in the US; Portland, Maine; Long Beach, California; and Montgomery County, Pennsylvania. Since these facilities started operations some 8--10 years ago, the Steinmuller mass burn grate system has undergone further development in order to adapt the system to new applications such as tire burning, burning of highly contaminated wood and the co-firing of sewage sludge, hospital waste and other portions of the waste stream. The paper gives a detailed overview of the new improved design of the grate and boiler system. The first section of the paper describes in detail the continuous improvement process for the design of the top supported boiler in conjunction with the grate hanging in the waterwalls. The new feed chute design and its modified geometry is described as well as the newly introduced high alloy cladding on the stoker side wall weartubes. The second section contains an outlook on the next generation of mass burn grate technology employing the new Steinmuller water cooled mass burn grate system, a quantum leap in stoker technology, Finally the paper summarizes the future potentials and directions of further research and development on the Steinmuller mass burn grate system for continuous applications well into the 21st century.

  12. Cooking on a closed fire

    Energy Technology Data Exchange (ETDEWEB)

    Ertmer, Katharina

    2010-07-01

    In rural areas of Africa, Asia and Latin America, wood is the most widespread raw material used to generate heat for cooking and heating. However, this use of biomass in such regions is generally viewed as being harmful to the climate, the environment and human health. Now the situation should be improved by the introduction of more efficient stoves to replace open fires. (orig.)

  13. MEMS Bragg grating force sensor

    DEFF Research Database (Denmark)

    Reck, Kasper; Thomsen, Erik Vilain; Hansen, Ole

    2011-01-01

    We present modeling, design, fabrication and characterization of a new type of all-optical frequency modulated MEMS force sensor based on a mechanically amplified double clamped waveguide beam structure with integrated Bragg grating. The sensor is ideally suited for force measurements in harsh...... environments and for remote and distributed sensing and has a measured sensitivity of -14 nm/N, which is several times higher than what is obtained in conventional fiber Bragg grating force sensors. © 2011 Optical Society of America....

  14. US Fire Administration Fire Statistics

    Data.gov (United States)

    Department of Homeland Security — The U.S. Fire Administration collects data from a variety of sources to provide information and analyses on the status and scope of the fire problem in the United...

  15. Model based control of grate combustion; Modellbaserad roststyrning

    Energy Technology Data Exchange (ETDEWEB)

    Broden, Henrik; Kjellstroem, Bjoern; Niklasson, Fredrik; Boecher Poulsen, Kristian

    2006-12-15

    temperature did not appear to allow more rapid process control than measurements of output power and oxygen in the exhaust. Measurements of the bed height gave better control for disturbances of the fuel flow but not for disturbances of the fuel moisture. The conclusion is uncertain since the model is not sufficiently validated and gives unreasonable results for the bed height at the end of the grate. Too long time intervals for collection of data, in particular for fuel moisture, and uncertainties in measured air flows are the main reasons for shortcomings in the validation. The preliminary conclusion is that measurements of grate temperatures do not provide information that can be used for more rapid control of grate firing for disturbances caused by variations in fuel moisture and fuel flow. Measurements of bed heights may allow better control. The objectives of the project have been partly reached.

  16. Fire in ice: two millennia of boreal forest fire history from the Greenland NEEM ice core

    OpenAIRE

    Zennaro, P.; Kehrwald, N.; McConnell, J. R.; Schüpbach, Simon; O. J. Maselli; J. Marlon; Vallelonga, P.; Leuenberger, Daiana; Zangrando, R.; A. Spolaor; Borrotti, M.; Barbaro, E.; Gambaro, A.; C. Barbante

    2014-01-01

    Biomass burning is a major source of greenhouse gases and influences regional to global climate. Pre-industrial fire-history records from black carbon, charcoal and other proxies provide baseline estimates of biomass burning at local to global scales spanning millennia, and are thus useful to examine the role of fire in the carbon cycle and climate system. Here we use the specific biomarker levoglucosan together with black carbon and ammonium concentrations from the North Greenland Eemian (NE...

  17. Fire in ice: two millennia of boreal forest fire history from the Greenland NEEM ice core

    OpenAIRE

    Zennaro, P.; Kehrwald, N.; McConnell, J. R.; S. Schüpbach; O. J. Maselli; J. Marlon; Vallelonga, P.; Leuenberger, D.; Zangrando, R.; A. Spolaor; Borrotti, M.; Barbaro, E.; Gambaro, A.; C. Barbante

    2014-01-01

    Biomass burning is a major source of greenhouse gases and influences regional to global climate. Pre-industrial fire-history records from black carbon, charcoal and other proxies provide baseline estimates of biomass burning at local to global scales spanning millennia, and are thus useful to examine the role of fire in the carbon cycle and climate system. Here we use the specific biomarker levoglucosan together with black carbon and ammonium concentrations from the North Gr...

  18. A fundamental study of biomass oxy-fuel combustion and co-combustion

    OpenAIRE

    Farrow, Timipere Salome

    2013-01-01

    While oxy-fuel combustion research is developing and large scale projects are proceeding, little information is available on oxy-biomass combustion and cocombustion with coal. To address this knowledge gap, this research conducted has involved comprehensive laboratory based fundamental investigation of biomass firing and co-firing under oxy-fuel conditions and compared it to conventional air firing conditions. First, TGA was employed to understand the fundamental behaviour of biomass devolati...

  19. Theoretical analysis of novel fiber grating pair

    Science.gov (United States)

    Wang, Liao; Jia, Hongzhi; Fang, Liang; You, Bei

    2016-06-01

    A novel fiber grating pair that consists of a conventional long-period fiber grating and a fiber Bragg cladding grating (FBCG) is proposed. The FBCG is a new type of fiber grating in which refractive index modulation is formed in the cladding. Through the coupled-mode theory, we accurately calculate the coupling coefficients between modes supported in the fibers. And some other mode coupling features in the fiber cladding gratings are analyzed in detail. The calculation of the modes involved in this paper is based on a model of three-layer step-index fiber geometry. Then, we have investigated the sensitivity characteristics for variation of the modulation strengths of the fiber Bragg cladding gratings' resonance peaks and the long-period cladding gratings' (LPCGs) dual resonant peaks. Finally, the modulation strength sensitivity of the grating pair's three resonant peaks is demonstrated, and the results indicate that these grating pairs may find potential applications in optical fiber sensing.

  20. The role of semi-volatile organic compounds in the mesoscale evolution of biomass burning aerosol: a modelling case study of the 2010 mega-fire event in Russia

    Directory of Open Access Journals (Sweden)

    I. B. Konovalov

    2015-03-01

    Full Text Available Chemistry transport models (CTMs are an indispensable tool for studying and predicting atmospheric and climate effects associated with carbonaceous aerosol from open biomass burning (BB; this type of aerosol is known to contribute significantly to both global radiative forcing and to episodes of air pollution in regions affected by wildfires. Improving model performance requires systematic comparison of simulation results with measurements of BB aerosol and elucidating possible reasons for discrepancies between them, which, "by default", are frequently attributed in the literature to uncertainties in emission data. Based on published laboratory data regarding atmospheric evolution of BB aerosol and by using the volatility basis set (VBS approach to organic aerosol modeling along with a "conventional" approach, we examined the importance of taking gas-particle partitioning and oxidation of semi-volatile organic compounds (SVOCs into account in simulations of the mesoscale evolution of smoke plumes from intense wildfires that occurred in western Russia in 2010. BB emissions of primary aerosol components were constrained with the PM10 and CO data from the air pollution monitoring network in the Moscow region. The results of the simulations performed with the CHIMERE CTM were evaluated by considering, in particular, the ratio of smoke-related enhancements in PM10 and CO concentrations (ΔPM10 and ΔCO measured in Finland (in the city of Kuopio, nearly 1000 km downstream of the fire emission sources. It is found that while the conventional approach (disregarding oxidation of SVOCs and assuming organic aerosol material to be non-volatile strongly underestimates values of ΔPM10/ΔCO observed in Kuopio (by almost a factor of two, the VBS approach is capable to bring the simulations to a reasonable agreement with the ground measurements both in Moscow and in Kuopio. Using the VBS instead of the conventional approach is also found to result in a major

  1. Stratifying Tropical Fires by Land Cover: Insights into Amazonian Fires, Aerosol Loading, and Regional Deforestation

    Science.gov (United States)

    TenHoeve, J. E.; Remer, L. A.; Jacobson, M. Z.

    2010-01-01

    This study analyzes changes in the number of fires detected on forest, grass, and transition lands during the 2002-2009 biomass burning seasons using fire detection data and co-located land cover classifications from the Moderate Resolution Imaging Spectroradiometer (MODIS). We find that the total number of detected fires correlates well with MODIS mean aerosol optical depth (AOD) from year to year, in accord with other studies. However, we also show that the ratio of forest to savanna fires varies substantially from year to year. Forest fires have trended downward, on average, since the beginning of 2006 despite a modest increase in 2007. Our study suggests that high particulate matter loading detected in 2007 was likely due to a large number of savanna/agricultural fires that year. Finally, we illustrate that the correlation between annual Brazilian deforestation estimates and MODIS fires is considerably higher when fires are stratified by MODIS-derived land cover classifications.

  2. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

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

    In this literature report is provided a status for the present knowledge level on ash properties when co-firing coal and biomass. The fly ash formed in boilers using co-firing of coal and straw do have a large influence on ash deposit formation, boiler corrosion, fly ash utilization and operation...

  3. Energy production from marine biomass (Ulva lactuca)

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaisen, L.; Daugbjerg Jensen, P.; Svane Bech, K. [Danish Technological Institute (DTI), Taastrup (Denmark)] [and others

    2011-11-15

    In this project, methods for producing liquid, gaseous and solid biofuel from the marine macroalgae Ulva lactuca has been studied. To get an understanding of the growth conditions of Ulva lactuca, laboratory scale growth experiments describing N, P, and CO{sub 2} uptake and possible N{sub 2}O and CH{sub 4} production are carried out. The macroalgae have been converted to bioethanol and methane (biogas) in laboratory processes. Further the potential of using the algae as a solid combustible biofuel is studied. Harvest and conditioning procedures are described together with the potential of integrating macroalgae production at a power plant. The overall conclusions are: 1. Annual yield of Ulva lactuca is 4-5 times land-based energy crops. 2. Potential for increased growth rate when bubbling with flue gas is up to 20%. 3. Ethanol/butanol can be produced from pretreated Ulva of C6 and - for butanol - also C5 sugars. Fermentation inhibitors can possibly be removed by mechanical pressing. The ethanol production is 0,14 gram pr gram dry Ulva lactuca. The butanol production is lower. 4. Methane yields of Ulva are at a level between cow manure and energy crops. 5. Fast pyrolysis produces algae oil which contains 78 % of the energy content of the biomass. 6. Catalytic supercritical water gasification of Ulva lactuca is feasible and a methane rich gas can be obtained. 7. Thermal conversion of Ulva is possible with special equipment as low temperature gasification and grate firing. 8. Co-firing of Ulva with coal in power plants is limited due to high ash content. 9. Production of Ulva only for energy purposes at power plants is too costly. 10. N{sub 2}O emission has been observed in lab scale, but not in pilot scale production. 11. Analyses of ash from Ulva lactuca indicates it as a source for high value fertilizers. 12. Co-digestion of Ulva lactuca together with cattle manure did not alter the overall fertilization value of the digested cattle manure alone. (LN)

  4. Solid biomass barometer - EurObserv'ER - December 2012

    International Nuclear Information System (INIS)

    The winter of 2011 was exceptionally mild, even in Northern Europe, with unusually high temperatures. As a result the demand for firewood and solid biomass fuel was low. The European Union's primary energy production from solid biomass between 2010 and 2011 contracted by 2.9% slipping to 78.8 Mtoe. Solid biomass electricity production continued to grow, driven by the additional take-up of biomass co-firing

  5. Smouldering Subsurface Fires in the Earth System

    Science.gov (United States)

    Rein, Guillermo

    2010-05-01

    Smouldering fires, the slow, low-temperature, flameless form of combustion, are an important phenomena in the Earth system. These fires propagate slowly through organic layers of the forest ground and are responsible for 50% or more of the total biomass consumed during wildfires. Only after the 2002 study of the 1997 extreme haze event in South-East Asia, the scientific community recognised the environmental and economic threats posed by subsurface fires. This was caused by the spread of vast biomass fires in Indonesia, burning below the surface for months during the El Niño climate event. It has been calculated that these fires released between 0.81 and 2.57 Gton of carbon gases (13-40% of global emissions). Large smouldering fires are rare events at the local scale but occur regularly at a global scale. Once ignited, they are particularly difficult to extinguish despite extensive rains or fire-fighting attempts and can persist for long periods of time (months, years) spreading over very extensive areas of forest and deep into the soil. Indeed, these are the oldest continuously burning fires on Earth. Earth scientists are interested in smouldering fires because they destroy large amounts of biomass and cause greater damage to the soil ecosystem than flaming fires do. Moreover, these fires cannot be detected with current satellite remote sensing technologies causing inconsistencies between emission inventories and model predictions. Organic soils sustain smouldering fire (hummus, duff, peat and coal) which total carbon pool exceeds that of the world's forests or the atmosphere. This have important implications for climate change. Warmer temperatures at high latitudes are resulting in unprecedented permafrost thaw that is leaving large soil carbon pools exposed to fires. Because the CO2 flux from peat fires has been measured to be about 3000 times larger that the natural degradation flux, permafrost thaw is a risk for greater carbon release by fire and subsequently

  6. Biomass Cofiring in Coal Power Plants and its Impact on Agriculture in the United States

    OpenAIRE

    Dumortier, Jerome

    2012-01-01

    We analyze the effects on local biomass supply, demand, and prices of co-firing requirement for existing coal-fired power plants. The co-firing requirement is imposed on 398 existing power plants. The biomass feedstock can come from corn stover, wheat straw, switchgrass, and/or forest residues. Our model incorporates county-level biomass supply as well as national crop commodity demand. A solution to the model consists of county biomass prices and national crop prices. Keywords: Biomass, co-f...

  7. Post-fire Soil Microbial Biomass and Nutrient Content of Larix gmelinii Forest in Autumn%兴安落叶松林火后对土壤养分和土壤微生物生物量的影响

    Institute of Scientific and Technical Information of China (English)

    赵彬; 孙龙; 胡海清; 孙志虎

    2011-01-01

    For the aim of understanding the relationships between the soil microbial biomass and nutrient content after fire in Larix gmelinii forest in Da Hinggan Mountains of China, detailed field investigations were conducted in burned area with different fire intensities (serious, medium and low fire intensity). To find the impact factors of microbial biomass, we measured soil microbial biomass carbon ( Cmic ), nitrogen ( Nmic ) and soil nutrient of different fire intensities with a fumigation-extraction method after burned three years. The results showed that the Cmic in serious burned site was significantly higher than in the medium, low and unburned sites. Though the Nmic has no significant effect in different treatments, yet it was the biggest in serious burned site. Mean soil Cmic in serious burned site was different significantly with medium, low and unburned sites. The mean Cmic of serious, medium, low and unburned sites was 692. 8,499. 9,428.8 and 498.7 mg · kg-1, and the mean Nmic was 70. 6, 55.2, 50. 9 and 54. 1 mg · kg-1, respectively. The content of soil organic carbon and total N in serious burned area was 82. 6 g · kg- 1 and 4. 9 g · kg - 1 respectively, which was higher than in the unburned area significantly and presented an ascending trend with the increase of fire intensity. The content of soil total phosphorus increased significantly, but it has no significant difference among different fire intensities. Soil available phosphorus content increased in light burned area significantly, which was 29. 9 mg · kg-1, but a decrease occurred with the increase of fire intensities. Soil moisture content, pH and soil organic carbon influenced the Cmic and Nmic significantly, the soil microbial biomass was positively correlated to the soil moisture content, pH and soil organic carbon.%以大兴安岭兴安落叶松林火后不同强度(重度、中度、轻度)及未火烧区的土壤为研究对象,于火烧结束3年后(2009年)的秋季,采用氯仿熏蒸

  8. Biomass energy

    International Nuclear Information System (INIS)

    Bioenergy systems can provide an energy supply that is environmentally sound and sustainable, although, like all energy systems, they have an environmental impact. The impact often depends more on the way the whole system is managed than on the fuel or on the conversion technology. The authors first describe traditional biomass systems: combustion and deforestation; health impact; charcoal conversion; and agricultural residues. A discussion of modern biomass systems follows: biogas; producer gas; alcohol fuels; modern wood fuel resources; and modern biomass combustion. The issue of bioenergy and the environment (land use; air pollution; water; socioeconomic impacts) and a discussion of sustainable bioenergy use complete the paper. 53 refs., 9 figs., 14 tabs

  9. A Path Forward for Low Carbon Power from Biomass

    Directory of Open Access Journals (Sweden)

    Amanda D. Cuellar

    2015-02-01

    Full Text Available The two major pathways for energy utilization from biomass are conversion to a liquid fuel (i.e., biofuels or conversion to electricity (i.e., biopower. In the United States (US, biomass policy has focused on biofuels. However, this paper will investigate three options for biopower: low co-firing (co-firing scenarios refer to combusting a given percentage of biomass with coal (5%–10% biomass, medium co-firing (15%–20% biomass, and dedicated biomass firing (100% biomass. We analyze the economic and greenhouse gas (GHG emissions impact of each of these options, with and without CO2 capture and storage (CCS. Our analysis shows that in the absence of land use change emissions, all biomass co-combustion scenarios result in a decrease in GHG emissions over coal generation alone. The two biggest barriers to biopower are concerns about carbon neutrality of biomass fuels and the high cost compared to today’s electricity prices. This paper recommends two policy actions. First, the need to define sustainability criteria and initiate a certification process so that biomass providers have a fixed set of guidelines to determine whether their feedstocks qualify as renewable energy sources. Second, the need for a consistent, predictable policy that provides the economic incentives to make biopower economically attractive.

  10. Novel Bandwidth Sensor Based Fiber Grating

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, the basic principle and the design method of the bandwidth sensing of fiber grating are expounded, respectively. Several novel bandwidth sensor based fiber grating are analyzed and discussed.

  11. High Efficiency Low Scatter Echelle Grating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A high efficiency low scatter echelle grating will be developed using a novel technique of multiple diamond shaving cuts. The grating will have mirror surfaces on...

  12. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren;

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  13. Quantification and use of forest biomass residues in Maputo province, Mozambique

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, H.; Costa, M. [Mechanical Engineering Department, Institute Superior Tecnico, Technical University of Lisbon, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal)

    2009-09-15

    This article describes a study on the quantification and use of forest biomass residues in Maputo province, in Mozambique. The study was performed based on information from the thematic cartography of soils of Maputo province, provided by the National Direction of Forest and Land of Mozambique, and data for the forest growth rates available in the literature. It was estimated that the total production of forest biomass residues in Maputo province is 1,233,412 ton/year, with a corresponding energy potential of 17,267,771 GJ/year. As a way of making the forest biomass residues profitable, the present work proposes the use of part of the residues as fuel in new power plants to be build in Maputo province. In this part of the study aiming at implanting power plants in Maputo province, it was taken into account the risk of forest fires, number of existing consumers of forest residues, residues availability, protected forests, transport infrastructures and existence of national electric network. It was found that the districts of Magude and Moamba are those that have the best conditions to receive the new biomass power plants. Factors such as the cost of the technology and the degree of pre-treatment of the forest residues have been taken into consideration in choosing the combustion technology for the proposed power plants. In this context, the grate burning technology appears to be the most advantageous from costs/benefits viewpoint. The proposed power plants can produce about 236,520 MWh, which is equivalent to 32% of the energy consumed in Maputo province in 2004. (author)

  14. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2002-01-01

    demonstration of a two-stage gasification process through construction of several plants.} A preliminary analysis of the ideal recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained...... for the indirectly fired gas turbine (IFGT) and for the supplementary-fired IFGT. Both results show that the combination of external firing and internal firing have the potential of reducing or solving some problems with the use of biomass both in the recuperated and the indirectly fired gas turbine: The former...... to be independent of temperature ratio and lower than for the recuperated gas turbine....

  15. Proceedings of the fifth International Slovak Biomass Forum (ISBF)

    International Nuclear Information System (INIS)

    The publication has been set up as a proceedings of the conference dealing with use of biomass for energy production. The main conference topics are focused on the following scopes: Session 1: RES Policies, strategies, political background; Session 2: Bioenergy markets, tools and influence factors; Session 3: Biomass fuels production and trading; Parallel Session 4: Biomass firing technologies; Parallel Session 5: Municipal projects uptake; Parallel Session 6: Biomass large and small CHP; Parallel Session 7: Environmental biomass technologies; Session 8: Biomass projects financing roundtable; In this proceedings 54 contributions is included

  16. Grating-Coupled Waveguide Cloaking

    Institute of Scientific and Technical Information of China (English)

    WANG Jia-Fu; QU Shao-Bo; XU Zhuo; MA Hua; WANG Cong-Min; XIA Song; WANG Xin-Hua; ZHOU Hang

    2012-01-01

    Based on the concept of a grating-coupled waveguide (GCW),a new strategy for realizing EM cloaking is presented.Using metallic grating,incident waves are firstly coupled into the effective waveguide and then decoupled into free space behind,enabling EM waves to pass around the obstacle.Phase compensation in the waveguide keeps the wave-front shape behind the obstacle unchanged.Circular,rectangular and triangular cloaks are presented to verify the robustness of the GCW cloaking.Electric field animations and radar cross section (RCS)comparisons convincingly demonstrate the cloaking effect.

  17. Biomass recalcitrance

    DEFF Research Database (Denmark)

    Felby, Claus

    2009-01-01

    , to resistance to enzymatic deconstruction, with the aim of discovering new cost-effective technologies for biorefineries. It contains chapters on topics extending from the highest levels of biorefinery design and biomass life-cycle analysis, to detailed aspects of plant cell wall structure, chemical treatments...... of plant cell wall structure, chemical treatments, enzymatic hydrolysis, and product fermentation options. "Biomass Recalcitrance" is essential reading for researchers, process chemists and engineers working in biomass conversion, also plant scientists working in cell wall biology and plant biotechnology.......Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes...

  18. Biomass [updated

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow Jr, Anthony F [ORNL

    2016-01-01

    Biomass resources and conversion technologies are diverse. Substantial biomass resources exist including woody crops, herbaceous perennials and annuals, forest resources, agricultural residues, and algae. Conversion processes available include fermentation, gasification, pyrolysis, anaerobic digestion, combustion, and transesterification. Bioderived products include liquid fuels (e.g. ethanol, biodiesel, and gasoline and diesel substitutes), gases, electricity, biochemical, and wood pellets. At present the major sources of biomass-derived liquid fuels are from first generation biofuels; ethanol from maize and sugar cane (89 billion L in 2013) and biodiesel from vegetable oils and fats (24 billion liters in 2011). For other than traditional uses, policy in the forms of mandates, targets, subsidies, and greenhouse gas emission targets has largely been driving biomass utilization. Second generation biofuels have been slow to take off.

  19. Unprecedented Fires in Southern Africa

    Science.gov (United States)

    2002-01-01

    The fires that raged across southern Africa this August and September produced a thick 'river of smoke' over the region. NASA-supported studies currently underway on the event will contribute to improved air pollution policies in the region and a better understanding of its impact on climate change. This year the southern African fire season peaked in early September. The region is subject to some of the highest levels of biomass burning in the world. The heaviest burning was in western Zambia, southern Angola, northern Namibia, and northern Botswana. Some of the blazes had fire fronts 20 miles long that lasted for days. In this animation, multiple fires are burning across the southern part of the African continent in September 2000. The fires, indicated in red, were observed by the Advanced Very High Resolution Radiometer (AVHRR) instrument on board the NOAA-14 satellite. The fires generated large amounts of heat-absorbing aerosols (the dark haze), which were observed with the Earth Probe Total Ozone Mapping Spectrometer (TOMS) instrument. These observations were collected as part of a NASA-supported field campaign called SAFARI 2000 (Southern African Regional Science Initiative). The recent six-week 'dry-season' portion of this experiment was planned to coincide with the annual fires. SAFARI 2000 planners tracked the changing location of fires with daily satellite maps provided by researchers at NASA's Goddard Space Flight Center. 'Every year African biomass burning greatly exceeds the scale of the fires seen this year in the western United States,' says Robert Swap of the University of Virginia, one of the campaign organizers. 'But the southern African fire season we just observed may turn out to be an extreme one even by African standards. It was amazing how quickly this region went up in flames.' The thick haze layer from these fires was heavier than campaign participants had seen in previous field studies in the Amazon Basin and during the Kuwati oil fires

  20. Fire Power

    Science.gov (United States)

    Denker, Deb; West, Lee

    2009-01-01

    For education administrators, campus fires are not only a distressing loss, but also a stark reminder that a campus faces risks that require special vigilance. In many ways, campuses resemble small communities, with areas for living, working and relaxing. A residence hall fire may raise the specter of careless youth, often with the complication of…

  1. Returning Fire

    Science.gov (United States)

    Gould, Jon B.

    2007-01-01

    Last December saw another predictable report from the Foundation for Individual Rights in Education (FIRE), a self-described watchdog group, highlighting how higher education is supposedly under siege from a politically correct plague of so-called hate-speech codes. In that report, FIRE declared that as many as 96 percent of top-ranked colleges…

  2. On fire

    DEFF Research Database (Denmark)

    Hansen, Helle Rabøl

    The title of this paper: “On fire”, refers to two (maybe three) aspects: firstly as a metaphor of having engagement in a community of practice according to Lave & Wenger (1991), and secondly it refers to the concrete element “fire” in the work of the fire fighters – and thirdly fire as a signifier...

  3. Efficient iterative technique for designing bragg gratings

    DEFF Research Database (Denmark)

    Plougmann, Nikolai; Kristensen, Martin

    2004-01-01

    We present a new iterative method for designing Bragg gratings based on the Levenberg-Marquardt method of minimizing a chi-squared merit function. It is effective for designing both weak and strong gratings and is particularly well suited for unchirped gratings....

  4. Gratings in passive and active optical waveguides

    DEFF Research Database (Denmark)

    Berendt, Martin Ole

    1999-01-01

    This research project has focused on gratings in optical waveguides. These gratings may be produced by UV photon imprinting in optical fibers or planar technology waveguides. The gratings are optical waveguide equivalents of bulk dielectric mirrors or diffraction grating. For a grating in a waveg......This research project has focused on gratings in optical waveguides. These gratings may be produced by UV photon imprinting in optical fibers or planar technology waveguides. The gratings are optical waveguide equivalents of bulk dielectric mirrors or diffraction grating. For a grating...... mode losses confirmed. An elaborated grating model, including the detailed shape of the index modulation, has been developed. This model improves the interpretation of grating growth dynamic, which is of value to both; analysis of the UV imprinting set-ups, and to the investigation of photosensitivity...... mechanisms in silica. An other important part of the project aimed at perfection of distributed feed back DFB fiber lasers. At the outset of this project, DFB fiber lasers had been demonstrated, now the DFB fiber lasers are in commercial production. One of the problems that had to be overcome was to secure...

  5. Hybrid grating reflectors: Origin of ultrabroad stopband

    DEFF Research Database (Denmark)

    Park, Gyeong Cheol; Taghizadeh, Alireza; Chung, Il-Sug

    2016-01-01

    Hybrid grating (HG) reflectors with a high-refractive-index cap layer added onto a high contrast grating (HCG) provide a high reflectance close to 100% over a broader wavelength range than HCGs. The combination of a cap layer and a grating layer brings a strong Fabry-Perot (FP) resonance as well...

  6. Tunable Fiber Gratings and Their Applications

    Institute of Scientific and Technical Information of China (English)

    Z.; Fang; L.; Zhao; L.; Li; K.; Gao; Y.; Zhou; J.; Geng; R.; Qu; G.; Chen

    2003-01-01

    Some practical research topics on tunable fiber gratings in author's group are presented, including tuning speed, tuning range, tuning characteristics of gratings in HB fiber, and the tunability of the line-width. The applications of fiber gratings in communication and sensing are also discussed.

  7. Holocene fire dynamics in Fennoscandia

    Science.gov (United States)

    Clear, Jennifer; Seppa, Heikki; Kuosmanen, Niina; Molinari, Chiara; Lehsten, Veiko; Allen, Katherine; Bradshaw, Richard

    2015-04-01

    Prescribed burning is advocated in Fennoscandia to promote regeneration and to encourage biodiversity. This method of forest management is based on the perception that fire was much more frequent in the recent past and over a century of active fire suppression has created a boreal forest ecosystem almost free of natural fire. The absence of fire is thought to have contributed to the widespread dominance of Picea abies (Norway spruce) with the successive spruce dominated forest further reducing fire ignition potential. However, humans have altered the natural fire dynamics of Fennoscandia since the early- to mid-Holocene and disentangling the anthropogenic driven fire dynamics from the natural fire dynamics is challenging. Through palaeoecology and sedimentary charcoal deposits we are able to explore the Holocene spatial and temporal variability and changing drivers of fire and vegetation dynamics in Fennoscandia. At the local-scale, two forest hollow environments (<20km apart) were analysed for high resolution macroscopic charcoal and pollen analysis and their fire and vegetation history are compared to identify unique and mutual changes in disturbance history. Pollen derived quantitative reconstruction of vegetation at both the local- and regional-scale identifies local-scale disturbance dynamics and large-scale ecosystem response. Spatio-temporal heterogeneity and variability in biomass burning is explored throughout Fennoscandia and Denmark to identify the changing drives of fire dynamics throughout the Holocene. Palaeo-vegetation reconstructions are compared to process-based, climate driven dynamic vegetation model output to test the significance of fire frequency as a driver of vegetation composition and dynamics. Early-Holocene fire regimes in Fennoscandia are driven by natural climate variations and fuel availability. The establishment and spread of Norway spruce is driven by an increase in continentality of climate, but local natural and anthropogenic

  8. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length...

  9. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.820 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven...

  10. Economics of power generation from imported biomass

    International Nuclear Information System (INIS)

    Attention is paid to the economics of import of biomass to the Netherlands, and subsequent utilisation for power generation, as a means to reduce dependence on (imported) fossil fuels and to reduce CO2 emission. Import of wood to the extent of 40 PJ or more from Baltic and South American states seems to be readily achievable. Import of biomass has various advantages, not only for the European Union (reduced CO2 emissions) but also for the countries of origin (employment creation). However, possible disadvantages or risks should be taken into account. With that in mind, import of biomass from Baltic states seems very interesting, although it should be noted that in some of those countries the alternative of fuel-switching to biomass seems to be more cost-effective than import of biomass from those countries. Given the expected increase in inland biomass consumption in the Baltic countries and the potential substantial future demand for biomass in other Western European countries it is expected that the biomass supply from Baltic countries will not be sufficient to fulfill the demand. An early focus on import from other countries seems advisable. Several power generation options are available with short to medium term potential and long term potential. The margin between costs of biomass-fuelled power and of coal fired power will be smaller, due to substantial improvements in power generating efficiency and reductions of investment costs of options for power generation from biomass, notably Biomass Gasification Combined Cycle. 18 refs

  11. Fiber Bragg grating with polyimide-silica hybrid membrane for accurately monitoring cell growth and temperature in a photobioreactor.

    Science.gov (United States)

    Zhong, Nianbing; Liao, Qiang; Zhu, Xun; Zhao, Mingfu

    2014-09-16

    A microstructured fiber Bragg grating (MSFBG) was created to accurately and simultaneously monitor the cell growth of photosynthetic bacteria (PSB) Rhodopseudomonas palustris CQK 01 and the temperature in a photobioreactor. The proposed sensor was made from an FBG unit that was separated into three regions, an unperturbed region, and two etched regions with smooth surfaces. The unperturbed grating region was employed to monitor the temperature. To eliminate the effects of the liquid concentration and temperature on the biomass, a polyimide-silica hybrid membrane was created and coated on an etched grating region to separate the liquids from the PSB; that is, this thinned region was developed to analyze the liquid concentration and temperature. Another etched grating region with a smaller diameter was used to determine the response to the temperature, biomass, and liquid concentration. In addition, two models were also presented to demonstrate accurate simultaneous measurement of the biomass and temperature. We discovered that the MSFBG sensor can rapidly and accurately determine the difference in the Bragg wavelength shifts caused by changes in the temperature, biomass, and liquid-phase concentration. The measured biomass is highly correlated with the real cell growth, with a correlation of 0.9438; the hydrogen production rate and temperature difference from metabolic heat production reached 1.97 mmol/L/h and 2.8 °C, respectively, in the PSB culture. PMID:25166743

  12. Biomass power; Biomasse-Energie

    Energy Technology Data Exchange (ETDEWEB)

    Woergetter, M.

    2003-07-01

    The author reports about use of biomass in Austria and Bavaria: power generation, production of biodiesel, bioethanol, energy efficiency of small biomass furnaces. (uke) [German] Bioenergie wird von breiten Kreisen als wichtiger Ansatz in Richtung einer nachhaltigen Entwicklung in Europa gesehen. Die Herausforderung liegt dabei im neuen Herangehen an Entscheidungen; Dimensionen der Wirtschaft, der Umwelt und der Gesellschaft sind dabei zu beruecksichtigen. Bioenergie ist somit keine reine Frage der Umwelt, sondern zielt auf den Umbau unseres Systems in Richtung Nachhaltigkeit. (orig.)

  13. Compact Imaging Spectrometer Utilizing Immersed Gratings

    Energy Technology Data Exchange (ETDEWEB)

    Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

    2006-03-21

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

  14. Calculation of thermal noise in grating reflectors

    CERN Document Server

    Heinert, Daniel; Friedrich, Daniel; Hild, Stefan; Kley, Ernst-Bernhard; Leavey, Sean; Martin, Iain W; Nawrodt, Ronny; Tünnermann, Andreas; Vyatchanin, Sergey P; Yamamoto, Kazuhiro

    2013-01-01

    Grating reflectors have been repeatedly discussed to improve the noise performance of metrological applications due to the reduction or absence of any coating material. So far, however, no quantitative estimate on the thermal noise of these reflective structures exists. In this work we present a theoretical calculation of a grating reflector's noise. We further apply it to a proposed 3rd generation gravitational wave detector. Depending on the grating geometry, the grating material and the temperature we obtain a thermal noise decrease by up to a factor of ten compared to conventional dielectric mirrors. Thus the use of grating reflectors can substantially improve the noise performance in metrological applications.

  15. Biomass potential

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, D. [VTT Energy, Espoo (Finland)

    1996-12-31

    Biomass resources of the industrialised countries are enormous, if only a small fraction of set-aside fields were used for energy crops. Forest resources could also be utilised more efficiently than at present for large-scale energy production. The energy content of the annual net growth of the total wood biomass is estimated to be 180 million toe in Europe without the former USSR, and about 50 million toe of that in the EC area, in 1990. Presently, the harvesting methods of forest biomass for energy production are not yet generally competitive. Among the most promising methods are integrated harvesting methods, which supply both raw material to the industry and wood fuel for energy production. Several new methods for separate harvesting of energy wood are being developed in many countries. (orig.)

  16. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K.; Keraenen, H. [Enviropower Inc., Espoo (Finland)

    1996-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  17. Fire safety

    Energy Technology Data Exchange (ETDEWEB)

    Keski-Rahkonen, O.; Bjoerkman, J.; Hostikka, S.; Mangs, J. [VTT Building Technology, Espoo (Finland); Huhtanen, R. [VTT Energy, Espoo (Finland); Palmen, H.; Salminen, A.; Turtola, A. [VTT Automation, Espoo (Finland)

    1998-07-01

    According to experience and probabilistic risk assessments, fires present a significant hazard in a nuclear power plant. Fires may be initial events for accidents or affect safety systems planned to prevent accidents and to mitigate their consequences. The project consists of theoretical work, experiments and simulations aiming to increase the fire safety at nuclear power plants. The project has four target areas: (1) to produce validated models for numerical simulation programmes, (2) to produce new information on the behavior of equipment in case of fire, (3) to study applicability of new active fire protecting systems in nuclear power plants, and (4) to obtain quantitative knowledge of ignitions induced by important electric devices in nuclear power plants. These topics have been solved mainly experimentally, but modelling at different level is used to interpret experimental data, and to allow easy generalisation and engineering use of the obtained data. Numerical fire simulation has concentrated in comparison of CFD modelling of room fires, and fire spreading on cables on experimental data. So far the success has been good to fair. A simple analytical and numerical model has been developed for fire effluents spreading beyond the room of origin in mechanically strongly ventilated compartments. For behaviour of equipment in fire several full scale and scaled down calorimetric experiments were carried out on electronic cabinets, as well as on horizontal and vertical cable trays. These were carried out to supply material for CFD numerical simulation code validation. Several analytical models were developed and validated against obtained experimental results to allow quick calculations for PSA estimates as well as inter- and extrapolations to slightly different objects. Response times of different commercial fire detectors were determined for different types of smoke, especially emanating from smoldering and flaming cables to facilitate selection of proper detector

  18. Emissions from Biomass Burning in the Yucatan

    Science.gov (United States)

    Yokelson, R.; Crounse, J. D.; DeCarlo, P. F.; Karl, T.; Urbanski, S.; Atlas, E.; Campos, T.; Shinozuka, Y.; Kapustin, V.; Clarke, A. D.; Weinheimer, A.; Knapp, D. J.; Montzka, D. D.; Holloway, J.; Weibring, P.; Flocke, F.; Zheng, W.; Toohey, D.; Wennberg, P. O.; Wiedinmyer, C.; Mauldin, L.; Fried, A.; Richter, D.; Walega, J.; Jimenez, J. L.

    2009-01-01

    In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle species were measured from 20 deforestation and crop residue fires on the Yucatan peninsula. This included two trace gases useful as indicaters of BB (HCN and acetonitrile) and several rarely, or never before, measured species: OH, peroxyacetic acid, propanoic acid, hydrogen peroxide, methane sulfonic acid, and sulfuric acid. Crop residue fires emitted more organic acids and ammonia than deforestation fires, but the emissions from the main fire types were otherwise fairly similar. The Yucatan fires emitted unusually amounts of SO2 and particle chloride, likely due to a strong marine influence on the peninsula.

  19. Effective grating theory for resonance domain surface-relief diffraction gratings.

    Science.gov (United States)

    Golub, Michael A; Friesem, Asher A

    2005-06-01

    An effective grating model, which generalizes effective-medium theory to the case of resonance domain surface-relief gratings, is presented. In addition to the zero order, it takes into account the first diffraction order, which obeys the Bragg condition. Modeling the surface-relief grating as an effective grating with two diffraction orders provides closed-form analytical relationships between efficiency and grating parameters. The aspect ratio, the grating period, and the required incidence angle that would lead to high diffraction efficiencies are predicted for TE and TM polarization and verified by rigorous numerical calculations.

  20. Dynamic analysis and temperature measurements of concrete cantilever beam using fibre Bragg gratings

    Science.gov (United States)

    da Silva, Jean Carlos Cardozo; Martelli, Cicero; Kalinowski, Hypolito José; Penner, Elisabeth; Canning, John; Groothoff, Nathaniel

    2007-01-01

    We analyzed the action of fire, causing degradation in a concrete cantilever beam using dynamic testing. The structure was fitted with two fibre Bragg gratings (FBG) sensors. One of them measured vibration and the other measured the temperature inside of the cantilever beam, while the beam was exposed to fire. A high-temperature probe based on a simple packaging system, which isolates the sensing FBG from any mechanical action, was developed. A low-cost fibre Bragg grating interrogation system, including easy assembly and maintenance, was used for the measurements. The temperature in the cantilever beam increased until 150 °C and a reduction in the strength of concrete was observed through modal analysis. Results reveal a considerable reduction in strength occurs even with exposures to moderate temperatures (less than 90 °C).

  1. Fiber Bragg Grating Based Thermometry

    OpenAIRE

    Ahmed, Zeeshan; Filla, James; Guthrie, William; Quintavalle, John

    2016-01-01

    In recent years there has been considerable interest in developing photonic temperature sensors such as the Fiber Bragg gratings (FBG) as an alternative to resistance thermometry. In this study we examine the thermal response of FBGs over the temperature range of 233 K to 393 K. We demonstrate, in a hermetically sealed dry Argon environment, that FBG devices show a quadratic dependence on temperature with expanded uncertainties (k = 2) of ~500 mK. Our measurements indicate that the combined m...

  2. Diffraction gratings for lighting applications

    Science.gov (United States)

    Cornelissen, Hugo J.; de Boer, Dick K. G.; Tukker, Teus

    2013-09-01

    Sub-micron diffraction gratings have been used for two LED illumination applications. One is to create a transparent see through luminaire which can be used to illuminate and read a paper document or e-book. A second is a light sensor that can be used in a feedback loop to control a multicolor LED lamp. Optical design and experimental proof-of-principle are presented.

  3. Biomass fuel characterization for NOx emissions in cofiring applications

    NARCIS (Netherlands)

    Di Nola, G.

    2007-01-01

    This dissertation investigates the impact of various biomass fuels and combustion conditions on the NOx emissions during biomass co-firing. Fossil fuels dominated the energy scenario since the industrial revolution. However, in the last decades, increasing concerns about their availability and envi

  4. Evaluating the SEVIRI Fire Thermal Anomaly Detection Algorithm across the Central African Republic Using the MODIS Active Fire Product

    OpenAIRE

    Freeborn, Patrick H.; Wooster, Martin J.; Gareth Roberts; Weidong Xu

    2014-01-01

    Satellite-based remote sensing of active fires is the only practical way to consistently and continuously monitor diurnal fluctuations in biomass burning from regional, to continental, to global scales. Failure to understand, quantify, and communicate the performance of an active fire detection algorithm, however, can lead to improper interpretations of the spatiotemporal distribution of biomass burning, and flawed estimates of fuel consumption and trace gas and aerosol emissions. This work e...

  5. High Temperature Corrosion in Biomass Incineration Plants

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Maahn, Ernst emanuel; Gotthjælp, K.;

    1997-01-01

    The aim of the project is to study the role of ash deposits in high temperature corrosion of superheater materials in biomass and refuse fire combined heat and power plants. The project has included the two main activities: a) A chemical characterisation of ash deposits collected from a major...

  6. Fire impacts on the cryosphere

    Science.gov (United States)

    Kehrwald, N. M.; Zennaro, P.; Skiles, M.; Barbante, C.

    2015-12-01

    Continental-scale smog clouds and massive boreal smoke plumes deposit dark particles on glaciers, darkening their surfaces and altering surface albedo. These atmospheric brown clouds are primarily comprised of both fossil fuel and biomass burning combustion products. Here, we examine the biomass burning contribution to aerosols trapped in the cryosphere through investigating the specific molecular marker levoglucosan (1,6-anhydro-β-D-glucopyranose) in ice cores. Levoglucosan is only produced by cellulose combustion, and therefore is an ideal comparison for multi-proxy investigations incorporating other markers with multiple sources. Wildfire combustion products are a major component of dark aerosols deposited on the Greenland ice sheet during the 2012 melt event. Levoglucosan concentrations that demonstrate the biomass burning contribution are similar to black carbon concentrations that record both fossil fuel and biomass burning during this same event. This similarity is especially important as levoglucosan and black carbon trends differ during the industrial era in the NEEM, Greenland ice core, demonstrating different contributions of fossil fuel and biomass burning to the Greenland ice sheet. These differences are also present in the EPICA Dome C Antarctic ice core. Low-latitude ice cores such as Kilimanjaro, Tanzania and Muztag, Tibet demonstrate that climate is still the primary control over fire activity in these regions, even with increased modern biomass burning and the possible impacts of atmospheric brown clouds.

  7. Varied line-space gratings and applications

    International Nuclear Information System (INIS)

    This paper presents a straightforward analytical and numerical method for the design of a specific type of varied line-space grating system. The mathematical development will assume plane or nearly-plane spherical gratings which are illuminated by convergent light, which covers many interesting cases for synchrotron radiation. The gratings discussed will have straight grooves whose spacing varies across the principal plane of the grating. Focal relationships and formulae for the optical grating-pole-to-exist-slit distance and grating radius previously presented by other authors will be derived with a symbolic algebra system. It is intended to provide the optical designer with the tools necessary to design such a system properly. Finally, some possible advantages and disadvantages for application to synchrotron to synchrotron radiation beamlines will be discussed

  8. The spectral combination characteristic of grating and the bi-grating diffraction imaging effect

    Institute of Scientific and Technical Information of China (English)

    ZHANG WeiPing; HE XiaoRong

    2007-01-01

    This paper reports on a new property of grating,namely spectral combination,and on bi-grating diffraction imaging that is based on spectral combination.The spectral combination characteristic of a grating is the capability of combining multiple light beams of different wavelengths incident from specific angles into a single beam.The bi-grating diffraction imaging is the formation of the image of an object with two gratings: the first grating disperses the multi-color light beams from the object and the second combines the dispersed light beams to form the image.We gave the conditions necessary for obtaining the spectral combination.We also presented the equations that relate the two gratings' spatial frequencies,diffraction orders and positions necessary for obtaining the bi-grating diffraction imaging.

  9. A review on advances of torrefaction technologies for biomass processing

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, Bimal; Sule, Idris; Dutta, Animesh [University of Guelph, School of Engineering, Guelph, ON (Canada)

    2012-12-15

    Torrefaction is a thermochemical pretreatment process at 200-300 C in an inert condition which transforms biomass into a relatively superior handling, milling, co-firing and clean renewable energy into solid biofuel. This increases the energy density, water resistance and grindability of biomass and makes it safe from biological degradation which ultimately makes easy and economical on transportation and storing of the torrefied products. Torrefied biomass is considered as improved version than the current wood pellet products and an environmentally friendly future alternative for coal. Torrefaction carries devolatilisation, depolymerization and carbonization of lignocellulose components and generates a brown to black solid biomass as a productive output with water, organics, lipids, alkalis, SiO{sub 2}, CO{sub 2}, CO and CH{sub 4}. During this process, 70 % of the mass is retained as a solid product, and retains 90 % of the initial energy content. The torrefied product is then shaped into pellets or briquettes that pack much more energy density than regular wood pellets. These properties minimize on the difference in combustion characteristics between biomass and coal that bring a huge possibility of direct firing of biomass in an existing coal-fired plant. Researchers are trying to find a solution to fire/co-fire torrefied biomass instead of coal in an existing coal-fired based boiler with minimum modifications and expenditures. Currently available torrefied technologies are basically designed and tested for woody biomass so further research is required to address on utilization of the agricultural biomass with technically and economically viable. This review covers the torrefaction technologies, its' applications, current status and future recommendations for further study. (orig.)

  10. Technology is not a barrier for biomass power: Experiences from 130 biomass power plants

    Energy Technology Data Exchange (ETDEWEB)

    Aijala, M.; Hulkkonen, S.

    1998-07-01

    Finland is one of the leading countries in the utilization of biomass fuels for power production. The biomass fuels in Finland are peat and wood biomass, which are also the only indigenous fuels available. Peat and wood biomass cover about 26% of the primary energy consumption in Finland and their share in power generation is about 18% (peat 8% and wood biomass 10%). There are about 230 biomass fired boilers in operation of which 130 are used for combined heat and power (CHP) production. The wood and peat-fired power plants range in size from a small CHP plant of 5 MWe to the largest condensing plant of 154 MWe. The most common technology today for the biomass fuels is fluidized bed combustion with back pressure steam cycle for district heat or process steam production. Bubbling fluidized bed (BFB) is best for wood and peat combustion and circulating fluidized bed (CFB) is needed, when coal is wanted as a back up fuel. The largest bubbling fluidized bed in Finland has a capacity of 295 MWth using peat and wood wastes as fuels. The smallest ones are only a few MWth. Circulating fluidized bed boilers range from 25 to 290 MWth in biomass applications. Condensing power generation from solid fuels in the relatively small size scale is not economical at todays conditions. Gasification is used only in a few small heating stations. One promising application area for the gasification technology, however, is in the co-combustion processes. The peat and wood biomass fuels are good fuels from combustion point of view, and do not create any major operating problems. The investment cost biomass fired CHP plants range from ECU 1,100 to 1,800/kWe depending on the size range. The costs of electricity in the municipal CHP plants is ECU 20-35/MWh. In industrial plants with longer operating time and low fuel price the cost of electricity can be even lower than ECU 17/MWh.

  11. COFIRING BIOMASS WITH LIGNITE COAL

    Energy Technology Data Exchange (ETDEWEB)

    Darren D. Schmidt

    2002-01-01

    The University of North Dakota Energy & Environmental Research Center, in support of the U.S. Department of Energy's (DOE) biomass cofiring program, completed a Phase 1 feasibility study investigating aspects of cofiring lignite coal with biomass relative to utility-scale systems, specifically focusing on a small stoker system located at the North Dakota State Penitentiary (NDSP) in Bismarck, North Dakota. A complete biomass resource assessment was completed, the stoker was redesigned to accept biomass, fuel characterization and fireside modeling tests were performed, and an engineering economic analysis was completed. In general, municipal wood residue was found to be the most viable fuel choice, and the modeling showed that fireside problems would be minimal. Experimental ash deposits from firing 50% biomass were found to be weaker and more friable compared to baseline lignite coal. Experimental sulfur and NO{sub x} emissions were reduced by up to 46%. The direct costs savings to NDSP, from cogeneration and fuel saving, results in a 15- to 20-year payback on a $1,680,000 investment, while the total benefits to the greater community would include reduced landfill burden, alleviation of fees for disposal by local businesses, and additional jobs created both for the stoker system as well as from the savings spread throughout the community.

  12. Fire - caribou - winter range relationships in northern Canada

    Directory of Open Access Journals (Sweden)

    D.C. Thomas

    1996-01-01

    Full Text Available We needed data on temporal changes in caribou forages after fire and relative use of age-classes of forests by caribou to help devise a fire suppression priority strategy for caribou winter range in north-central Canada. Consequently, from 1983 through 1986, we estimated the abundance of vegetation and relative use by caribou at 197 sites in western and eastern study areas on the winter range of the Beverly herd of caribou {Rangifer tarandus. Species of lichens attained peak biomass at different periods after fire - as early as 40-60 years for Cladonia spp. to > 150 years for Cladina rangiferina and Cetraria nivalis. Biomass of the primary "caribou lichen", Cladina mitis, increased rapidly from 21-30 years after fire to 41-50 years and attained maximum biomass at 81-90 yeats in the west and 41-60 years in the east. However, total lichen biomass increased with age of forest to 100-150 years because biomass of Stereocaulon spp. did not peak until after 100 years. The biomass of "caribou lichens" {Cladina spp. and Cetraria nivalis stabilized after 61-80 years in the west and 41-60 years in the east. The biomass of terrestrial lichen species can be predicted from their cover. Caribou lichen abundance apparently was only one of several factors that caused caribou to use stands 151-250 years after fire more than othet age classes.

  13. Advanced experimental applications for x-ray transmission gratings Spectroscopy using a novel grating fabrication method

    OpenAIRE

    Hurvitz, G.; Ehrlich, Y.; Strum, G.; Shpilman, Z.; Levy, I.; Fraenkel, M.

    2012-01-01

    A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses Focused-Ion-Beam (FIB) technology to fabricate high-quality free standing grating bars on Transmission Electron Microscopy grids (TEM-grid). High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100...

  14. Multilayer dielectric gratings for tiled-gratings compression of petawatt pulses.

    OpenAIRE

    Cotel, Arnaud

    2007-01-01

    Pulse compression diffraction gratings represent currently an important bottleneck for the development of energetic high-intensity Petawatt laser. Indeed, the laser-induced damage threshold of standard gold-coated gratings and the diffraction efficiency are limited. That's why we have developed a new generation of diffraction gratings: ! multilayer dielectric (MLD) gratings. Studies of MLD g! ratings applied to the Pico2000 laser project are the first part of my thesis work. On the other hand...

  15. Biomass shock pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  16. Torrefaction of biomass for power production

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti

    . Straw can be co-fired with coal in suspension fired power plants with a maximum straw share of 10 to 20 wt%. However, 100% straw firing induced several problems that can impede both boiler availability and power efficiency. Straw is highly fibrous and tenacious in nature, therefore a relatively high...... rates, relatively low superheater temperatures have to be applied, which in turn lower the power efficiency. The idea for this Ph.D. project is to develop a biomass pretreatment method that could provide the heating value of the fuel for the boiler, but in a way such that the fuel is easily pulverized.......D. thesis focus on the following subjects: 1) the development of experimental procedures for a novel laboratory scale reactor (simultaneous torrefaction and grinding) and a study on the torrefaction of straw and wood; 2) study the influence of biomass chemical properties such as ash content, ash composition...

  17. Evaluation of Various Solid Biomass Fuels Using Thermal Analysis and Gas Emission Tests

    OpenAIRE

    Hiroshi Koseki

    2011-01-01

    Various recently proposed biomass fuels are reviewed from the point of view of their safety. Many biomass materials are proposed for use as fuels, such as refuse derived fuel (RDF), wood chips, coal-wood mixtures, etc . However, these fuels have high energy potentials and can cause fires and explosions. We have experienced many such incidents. It is very difficult to extinguish fires in huge piles of biomass fuel or storage facilities. Here current studies on heat generation for these materia...

  18. Electrifying biomass

    International Nuclear Information System (INIS)

    British Columbia's (BC) energy plan was outlined in this PowerPoint presentation. BC Hydro is the third largest electric utility in Canada with a generating capacity of 11,000 MW, 90 per cent of which is hydro generation. Various independent power project (IPP) biomass technologies were outlined, including details of biogas, wood residue and municipal solid waste facilities. An outline of BC Hydro's overall supply mix was presented, along with details of the IPP supply mix. It was suggested that the cancellation of the Duke Point power project has driven growth in the renewable energy sector. A chart of potential energy contribution by resource type was presented, as well as unit energy cost ranges. Resources included small and large hydro; demand side management; resource smart natural gas; natural gas; coal; wind; geothermal; biomass; wave; and tidal. The acquisition process was reviewed. Details of calls for tenders were presented, and issues concerning bidder responsibility and self-selection were examined. It was observed that wood residue presents a firm source of electricity that is generally local, and has support from the public. In addition, permits for wood residue energy conversion are readily available. However, size limitations, fuel risks, and issues concerning site control may prove to be significant challenges. It was concluded that the success of biomass energy development will depend on adequate access and competitive pricing. tabs., figs

  19. Perfect crystallike gratings for cold neutrons

    International Nuclear Information System (INIS)

    We report on significant improvements of the performance of thick diffraction gratings for cold neutrons. The basis material for the production of holographic gratings by optical means is photosensitized deuterated poly(methyl methacrylate) (D-PMMA). The properties of these gratings now approach those of perfect monochromator crystals for neutrons of shorter wavelength: for cold neutrons with 1.0 nm wavelength the gratings exhibit a reflectivity in the percent range which makes them suitable for a wide range of applications in neutron optics

  20. Active Fire Mapping Program

    Science.gov (United States)

    Active Fire Mapping Program Current Large Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS Data Fire Data in Google Earth ...

  1. Fire Research Enclosure

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Simulates submarine fires, enclosed aircraft fires, and fires in enclosures at shore facilities . DESCRIPTION: FIRE I is a pressurizable, 324 cu m(11,400...

  2. Fuels and fire behavior dynamics on large-scale savanna fires in Kruger National Park, South Africa

    Science.gov (United States)

    Stocks, B. J.; van Wilgen, B. W.; Trollope, W. S. W.; McRae, D. J.; Mason, J. A.; Weirich, F.; Potgieter, A. L. F.

    1996-10-01

    Biomass characterization and fire behavior documentation were carried out on two large (>2000 ha) experimental fires conducted in arid savanna fuels in Kruger National Park in September 1992. Prefire fuel loads, fuel consumption, spread rates, flame zone characteristics, and in-fire and perimeter wind field dynamics were measured in order to determine overall energy release rates for each fire. Convection column dynamics were also measured in support of airborne trace gas and particulate measurements. Energy release rates varied significantly between the two fires, and this was strongly reflected in convection column development. The lower-intensity fire produced a weak, poorly defined smoke plume, while a well-developed column with a capping cumulus top developed during the higher intensity fire. Further experimental burning studies, in savannas with higher fuel loads, are recommended to further explore the fire behavior-convection column dynamics relationship investigated in this study.

  3. Extreme fire severity patterns in topographic, convective and wind-driven historical wildfires of Mediterranean pine forests.

    Directory of Open Access Journals (Sweden)

    Judit Lecina-Diaz

    Full Text Available Crown fires associated with extreme fire severity are extremely difficult to control. We have assessed fire severity using differenced Normalized Burn Ratio (dNBR from Landsat imagery in 15 historical wildfires of Pinus halepensis Mill. We have considered a wide range of innovative topographic, fuel and fire behavior variables with the purposes of (1 determining the variables that influence fire severity patterns among fires (considering the 15 wildfires together and (2 ascertaining whether different variables affect extreme fire severity within the three fire types (topographic, convective and wind-driven fires. The among-fires analysis showed that fires in less arid climates and with steeper slopes had more extreme severity. In less arid conditions there was more crown fuel accumulation and closer forest structures, promoting high vertical and horizontal fuel continuity and extreme fire severity. The analyses carried out for each fire separately (within fires showed more extreme fire severity in areas in northern aspects, with steeper slopes, with high crown biomass and in climates with more water availability. In northern aspects solar radiation was lower and fuels had less water limitation to growth which, combined with steeper slopes, produced more extreme severity. In topographic fires there was more extreme severity in northern aspects with steeper slopes and in areas with more water availability and high crown biomass; in convection-dominated fires there was also more extreme fire severity in northern aspects with high biomass; while in wind-driven fires there was only a slight interaction between biomass and water availability. This latter pattern could be related to the fact that wind-driven fires spread with high wind speed, which could have minimized the effect of other variables. In the future, and as a consequence of climate change, new zones with high crown biomass accumulated in non-common drought areas will be available to burn

  4. Fire, humans and landscape. Is there a connection?

    Science.gov (United States)

    Valese, Eva; Ascoli, Davide; Conedera, Marco; Held, Alex

    2013-04-01

    Fire evolved on the earth under the direct influence of climate and the accumulation of burnable biomass at various times and spatial scales. As a result, fire regimes depend not only on climatic and biological factors, but also greatly reflect the cultural background of how people do manage ecosystems and fire. A new awareness among scientists and managers has been rising about the ecological role of fire and the necessity to understand its past natural and cultural dynamics in different ecosystems, in order to preserve present ecosystem functionality and minimize management costs and negative impacts. As a consequence we assisted in the last decades to a general shift from the fire control to the fire management approach, where fire prevention, fire danger rating, fire ecology, fire pre-suppression and suppression strategies are fully integrated in the landscape management. Nowadays, a large number of authors recognize that a total suppression strategy, as the one adopted during last decades, leads to a fire paradox: the more we fight for putting out all fires, the more extreme events occur and cause long term damages. The aim of this review is to provide a state of art about the connection between fire, humans and landscape, along time and space. Negative and positive impacts on ecosystem services and values are put in evidence, as well as their incidence on human aptitude to fire use as to fire suppression. In order to capture a consistent fragment of fire history, palaeofires and related palynological studies are considered. They enable a valuable, even if partial, look at the millenary fire regime. Actual strategies and future directions are described in order to show what are the alternatives for living with fire, since removing completely this disturbance from earth is not a option, nor feasible neither advisable. Examples from the world, in particular from the Alps and the Mediterranean basin, are shown for better illustrating the signature of

  5. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    Directory of Open Access Journals (Sweden)

    Bjørn Qvale

    2003-06-01

    Full Text Available

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, supplementary firing is expected to result in a high marginal efficiency. The paper shows that depending on the application, this is not always the case.

    The interest in this cycle arises from a recent demonstration of the feasibility of a two-stage gasification process through construction of several plants. The gas from this process could be divided into two streams, one for primary and one for supplementary firing. A preliminary analysis of the ideal, recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained for the indirectly fired gas turbine (IFGT and for the supplementary-fired IFGT. These results show that the combination of external firing and internal firing have the potential of reducing or solving some problems associated with the use of biomass both in the recuperated and the indirectly fired gas turbine: The former requires a clean, expensive fuel. The latter is limited in efficiency due to limitations in material temperature of the heat exchanger. Thus, in the case of an IBFGT, it would appear be very appropriate to use a cheap biomass or waste fuel for low temperature combustion and external firing and use natural gas at a high marginal efficiency for high temperature heating. However, it is shown that this is not the case for a simple IBFGT supplementary-fired with natural gas. The marginal efficiency of the natural gas is in this case found to be independent of temperature ratio and lower than for the recuperated gas turbine. Instead, other process changes may be considered in order to obtain a high marginal efficiency on natural gas. Two possibilities

  6. Fire Brigade

    CERN Multimedia

    2004-01-01

    With effect from 15 April 2004, the Fire Brigade will no longer issue master keys on loan. Contractors' personnel requiring access to locked premises in order to carry out work must apply to the CERN staff member responsible for the contract concerned.

  7. Fiber Bragg Grating Based Thermometry

    CERN Document Server

    Ahmed, Zeeshan; Guthrie, William; Quintavalle, John

    2016-01-01

    In recent years there has been considerable interest in developing photonic temperature sensors such as the Fiber Bragg gratings (FBG) as an alternative to resistance thermometry. In this study we examine the thermal response of FBGs over the temperature range of 233 K to 393 K. We demonstrate, in a hermetically sealed dry Argon environment, that FBG devices show a quadratic dependence on temperature with expanded uncertainties (k = 2) of ~500 mK. Our measurements indicate that the combined measurement uncertainty is dominated by uncertainty in determining the peak center fitting and by thermal aging of polyimide coated fibers.

  8. Analytical and numerical study on grating depth effects in grating coupled waveguide sensors

    DEFF Research Database (Denmark)

    Horvath, R.; Wilcox, L.C.; Pedersen, H.C.;

    2005-01-01

    . Analytical expressions are derived both for the position and width of the in-coupling peaks to illustrate the effects of grating depth on the guided mode resonances in grating coupled waveguide sensors. Numerical computations verify the model for shallow gratings both in terms of peak shape and position......The in-coupling process for grating-coupled planar optical waveguide sensors is investigated in the case of TE waves. A simple analytical model based on the Rayleigh-Fourier-Kiselev method is applied to take into account the depth of the grating coupler, which is usually neglected in the modeling...

  9. Tilt sensitivity of the two-grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Christopher N.; Naulleau, Patrick P.

    2008-01-30

    Fringe formation in the two-grating interferometer is analyzed in the presence of a small parallelism error between the diffraction gratings assumed in the direction of grating shear. Our analysis shows that with partially coherent illumination, fringe contrast in the interference plane is reduced in the presence of nonzero grating tilt with the effect proportional to the grating tilt angle and the grating spatial frequencies. Our analysis also shows that for a given angle between the gratings there is an angle between the final grating and the interference plane that optimizes fringe contrast across the field.

  10. A review on biomass as a fuel for boilers

    Energy Technology Data Exchange (ETDEWEB)

    Saidur, R.; Abelaziz, E.A.; Demirbas, A.; Hossain, M.S.; Mekhilef, S. [University of Malaya, Kuala Lumpur (Malaysia). Dept. of Mechanical Engineering

    2011-06-15

    Currently, fossil fuels such as oil, coal and natural gas represent the prime energy sources in the world. However, it is anticipated that these sources of energy will deplete within the next 40-50 years. Moreover, the expected environmental damages such as the global warming, acid rain and urban smog due to the production of emissions from these sources have tempted the world to try to reduce carbon emissions by 80% and shift towards utilizing a variety of renewable energy resources (RES) which are less environmentally harmful such as solar, wind, biomass etc. in a sustainable way. Biomass is one of the earliest sources of energy with very specific properties. In this review, several aspects which are associated with burning biomass in boilers have been investigated such as composition of biomass, estimating the higher heating value of biomass, comparison between biomass and other fuels, combustion of biomass, co-firing of biomass and coal, impacts of biomass, economic and social analysis of biomass, transportation of biomass, densification of biomass, problems of biomass and future of biomass. It has been found that utilizing biomass in boilers offers many economical, social and environmental benefits such as financial net saving, conservation of fossil fuel resources, job opportunities creation and CO{sub 2} and NO emissions reduction. However, care should be taken to other environmental impacts of biomass such as land and water resources, soil erosion, loss of biodiversity and deforestation. Fouling, marketing, low heating value, storage and collections and handling are all associated problems when burning biomass in boilers. The future of biomass in boilers depends upon the development of the markets for fossil fuels and on policy decisions regarding the biomass market.

  11. Evaluating the sustainability of co-firing in the UK

    International Nuclear Information System (INIS)

    The objectives of the study were: Assess the overall carbon balance for co-firing; Investigate the other sustainability issues relating to co-firing; Assess the scope for incentivising the most sustainable forms of co-firing. The main questions to be addressed were: Is the overall carbon balance for co-firing positive? What is the difference in carbon balance between energy crops and other biomass? Are some kinds of energy crops better than others? How big a factor is transport in the carbon balance? Under what circumstances (fuel, transport, process, etc.) are the greatest benefits of co-firing in terms of carbon balance and sustainability? Are there any circumstances (as above) that could raise serious carbon balance or sustainability issues? How does the carbon balance compare between co-firing, dedicated biomass, and biomass heat? Is there any scope for encouraging the most sustainable forms of co-firing - perhaps through using existing or currently in development accreditation schemes? The report concludes that: Co-firing could be expanded to make a significant and low risk contribution to Government and EU renewable energy policy targets; Real environmental and social benefits could arise from the expansion of co-firing markets, both in the UK and in poor developing countries, given responsible development policy; There is no clear environmental or social case, for an arbitrary cap on the amount of co-firing; Co-firing could expand and enhance clean coal Carbon and Capture and Sequestration (CCS). This report focuses solely on the carbon (GHG) and broader sustainability impacts of co-firing in the UK. It does not include an economic evaluation. It provides an overview of the existing materials being used as feedstocks for co-firing and a summary life-cycle assessment of the GHG balances and sustainability (environmental and social) impacts of the provision and use of those feedstocks. A clear distinction is made between the use of residues and dedicated

  12. The spectral combination characteristic of grating and the bi-grating diffraction imaging effect

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper reports on a new property of grating, namely spectral combination, and on bi-grating diffraction imaging that is based on spectral combination. The spectral combination characteristic of a grating is the capability of combining multiple light beams of different wavelengths incident from specific angles into a single beam. The bi-grating diffraction imaging is the formation of the image of an object with two gratings: the first grating disperses the multi-color light beams from the object and the second combines the dispersed light beams to form the image. We gave the conditions necessary for obtaining the spectral combination. We also presented the equations that relate the two gratings’ spatial frequencies, diffraction orders and positions necessary for obtaining the bi-grating diffraction imaging.

  13. Inverse Scattering for Gratings and Wave Guides

    OpenAIRE

    Eskin, Gregory; Ralston, James; Yamamoto, Masahiro

    2007-01-01

    We consider the problem of unique identification of dielectric coefficients for gratings and sound speeds for wave guides from scattering data. We prove that the "propagating modes" given for all frequencies uniquely determine these coefficients. The gratings may contain conductors as well as dielectrics and the boundaries of the conductors are also determined by the propagating modes.

  14. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking...

  15. Reflectivity-modulated grating-mirror

    DEFF Research Database (Denmark)

    2012-01-01

    to the oscillation axis. A modulated voltage (91) is applied in reverse bias between the n- and p-doped layers to modulate the refractive index of the electrooptic material layer (12) and thereby the reflectivity spectrum of the grating mirror (1). The reflectivity of the grating mirror (1) can be modulated between...

  16. Antireflective characteristics of hemispherical grid grating

    Institute of Scientific and Technical Information of China (English)

    REN Zhibin; JIANG Huilin; LIU Guojun; SUN Qiang

    2005-01-01

    In this paper, the optical characteristics of new type hemispherical grid subwavelength grating are studied by using multi-level column structure approximation and rigorous coupled-wave analysis. This kind of grating could be fabricated by chemical methods, thus simplifying the fabrication technology of subwavelength gratings for visible light. By computer simulation and calculation, the hemispherical grid subwavelength gratings are proved to have antireflective characteristics. Two design schemes of this kind of grating are presented. In the first scheme, the grating could achieve a reflectivity as low as 3.4416×10-7, which can be adapted to 0.46―0.7 μm of visible waveband and ±12° incident angle field. In the second scheme, the grating can achieve a reflectivity as low as 3.112×10-4 and adapted to the whole visible waveband and ±23° incident angle field. The application field of the latter scheme is wider than that of the former. The results of this paper could provide reference for the applications of the hemispherical grid subwavelength gratings for the visible waveband.

  17. Satellite remote-sensing technologies used in forest fire management

    Institute of Scientific and Technical Information of China (English)

    TIAN Xiao-rui; Douglas J. Mcrae; SHU Li-fu; WANG Ming-yu; LI Hong

    2005-01-01

    Satellite remote sensing has become a primary data source for fire danger rating prediction, fuel and fire mapping, fire monitoring, and fire ecology research. This paper summarizes the research achievements in these research fields, and discusses the future trend in the use of satellite remote-sensing techniques in wildfire management. Fuel-type maps from remote-sensing data can now be produced at spatial and temporal scales quite adequate for operational fire management applications. US National Oceanic and Atmospheric Administration (NOAA) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellites are being used for fire detection worldwide due to their high temporal resolution and ability to detect fires in remote regions. Results can be quickly presented on many Websites providing a valuable service readily available to fire agency. As cost-effective tools, satellite remote-sensing techniques play an important role in fire mapping. Improved remote-sensing techniques have the potential to date older fire scars and provide estimates of burn severity. Satellite remote sensing is well suited to assessing the extent of biomass burning, a prerequisite for estimating emissions at regional and global scales, which are needed for better understanding the effects of fire on climate change. The types of satellites used in fire research are also discussed in the paper. Suggestions on what remote-sensing efforts should be completed in China to modernize fire management technology in this country are given.

  18. Alignment free characterization of 2D gratings

    CERN Document Server

    Madsen, Morten Hannibal; Hansen, Poul-Erik; Jørgensen, Jan Friis

    2015-01-01

    Fast characterization of 2-dimensional gratings is demonstrated using a Fourier lens optical system and a differential optimization algorithm. It is shown that both the grating specific parameters such as the basis vectors and the angle between them and the alignment of the sample, such as the rotation of the sample around the x-, y-, and z-axis, can be deduced from a single measurement. More specifically, the lattice vectors and the angle between them have been measured, while the corrections of the alignment parameters are used to improve the quality of the measurement, and hence reduce the measurement uncertainty. Alignment free characterization is demonstrated on both a 2D hexagonal grating with a period of 700 nm and a checkerboard grating with a pitch of 3000 nm. The method can also be used for both automatic alignment and in-line characterization of gratings.

  19. Compact imaging spectrometer utilizing immersed gratings

    Energy Technology Data Exchange (ETDEWEB)

    Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

    2007-07-03

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

  20. New field-based agricultural biomass burning trace gas, PM2.5, and black carbon emission ratios and factors measured in situ at crop residue fires in Eastern China

    Science.gov (United States)

    Zhang, Tianran; Wooster, Martin J.; Green, David C.; Main, Bruce

    2015-11-01

    Despite policy attempts to limit or prevent agricultural burning, its use to remove crop residues either immediately after harvest (e.g. field burning of wheat stubble) or after subsequent crop processing (e.g. "bonfires" of rice straw and rapeseed residues) appears to remain widespread across parts of China. Emission factors for these types of small but highly numerous fire are therefore required to fully assess their impact on atmospheric composition and air pollution. Here we describe the design and deployment of a new smoke measurement system for the close-range sampling of key gases and particles within smoke from crop residue fires, using it to assess instantaneous mixing ratios of CO and CO2 and mass concentrations of black carbon (BC) and PM2.5 from wheat stubble, rice straw, and rapeseed residue fires. Using data of our new smoke sampling system, we find a strong linear correlation between the PM2.5 mass and BC, with very high PM2.5 to BC emission ratios found in the smouldering phase (up to 80.7 mg m-3.(mg m-3)-1) compared to the flaming phase (2.0 mg m-3.(mg m-3)-1). We conclude that the contribution of BC to PM2.5 mass was as high as 50% in the flaming phase of some burns, whilst during smouldering it sometimes decreased to little over one percent. A linear mixing model is used to quantify the relative contribution of each combustion phase to the overall measured smoke composition, and we find that flaming combustion dominated the total emission of most species assessed. Using time series of trace gas concentrations from different fire cases, we calculated 'fire integrated' trace gas emission factors (EFs) for wheat, rice and rapeseed residue burns as 1739 ± 19 g kg-1, 1761 ± 30 g kg-1and 1704 ± 27 g kg-1 respectively for CO2, and 60 ± 12 g kg-1, 47 ± 19 g kg-1 and 82 ± 17 g kg-1 respectively for CO. Where comparisons were possible, our EFs agreed well with those derived via a simultaneously-deployed open path Fourier transform infrared (OP

  1. Fire Symfonier

    DEFF Research Database (Denmark)

    Nielsen, Svend Hvidtfelt

    2009-01-01

    sidste fire symfonier. Den er måske snarere at opfatte som et præludium til disse. At påstå, at symfonierne fra Holmboes side er planlagt til at være beslægtede, ville være at gå for vidt. Alene de 26 år, der skiller den 10. fra den 13., gør påstanden - i bedste fald - dubiøs. Når deres udformning...... udkrystallisering som i de sidste små 30 år af hans virke har afkastet disse fire variationer over en grundlæggende central holmboesk fornemmelse for form, melodi, klang og rytme. Denne oplevelse har fået mig til at udforske symfonierne, for at finde til bunds i dette holmboeske fællestræk, som jeg mener her står...

  2. Use of biomass for clean and efficient production of heat and power. Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Glarborg, P.; Lans, R. van der; Frandsen, J.B.F.; Johnsson, J.E.; Jensen, A.; Kiil, S.; Dam-Johansen, K.

    2001-03-01

    The present EFP98 project is the second phase of a long-term, strategic research project, the aim of which is to facilitate the use of significant amounts of biomass in the production of power and heat. The project deals with combustion and emission issues related to the use of biomass, specifically combustion of straw on a grate and wet flue gas desulphurization. A mathematical model for combustion of straw on a grate is developed as a tool to improve the understanding of this process. The model includes heat transfer to and in the bed as well as pyrolysis and char oxidation. To verify the model and to obtain a better understanding of fixed-bed straw combustion, a number of bench-scale laboratory experiments have been conducted at TNO in Holland. Predicted combustion rates and bed temperatures were in fairly good agreement with experimental fixed-bed data. A parameter analysis has identified the sensitivity of modeling predictions towards important parameters in the model. Measuring programs on straw firing have been conducted at Enstedvaerket and Masnedoe. Measuring results include gas temperature and gas composition (O{sub 2}, CO{sub 2}, CO. SO{sub 2}, NO) from different positions in the boiler. Data from Masnedoe include also results from co-firing of straw with other biomass fuels (25-35%). The results indicate that co-firing in the quantities does not significantly affect emissions. Nitrogen oxides emissions from Masnedoevaerket were found to be significantly higher than those of Ensted. The work on wet flue gas desulphurization on aimed to provide the information necessary to optimize and further develop the process. The main focus was fuel and sorbent flexibility, use of the waste product from the semi-dry FGD process as a sorbent in wet FGD, and ways of optimizing the Wet FGD process with respect to a high degree of desulphurization, a low content of residual limestone in the gypsum and a continuous steady state operation of the FGD plant. Laboratory

  3. Zaca Fire

    Science.gov (United States)

    2007-01-01

    On August 7, 2007, the Zaca fire continued to burn in the Los Padres National Forest near Santa Barbara, California. The fire started more than a month ago, on July 4, and has burned 69,800 acres. The fire remains in steep, rocky terrain with poor access. The continued poor access makes containment difficult in the wilderness area on the eastern flank. So far only one outbuilding has been destroyed; but over 450 homes are currently threatened. Over 2300 fire personnel, aided by four air tankers and 15 helicopters, are working to contain this massive fire. Full containment is expected on September 1. The image covers 45.2 x 46.1 km, and is centered near 34.6 degrees north latitude, 119.7 degrees west longitude. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Size: 45.2 by 46

  4. TG-FTIR experimental study on co-firing of biomass and coal%生物质与煤混烧的热重-红外试验研究

    Institute of Scientific and Technical Information of China (English)

    马爱玲; 谌伦建; 黄光许; 朱孔远

    2011-01-01

    The TG-FTIR analysis technology was applied to analyze the combustion process and products of coal, biomass and their mixtures, and the influence of biomass addition ratio, heating rate, oxygen concentration to the combustion process was also studied. The results show that biomass can improve the combustion characteristics and the burnout performance of sample. Increasing the biomass proportion, the CO and CO2 ratio in combustion gaseous products can be reduced, and the energy utilization efficiency can be improved. With the increase of heating rate and oxygen concentration, the burning speed of mixtures can be enhanced, the burning time can be shortened, the combustion performance can be improved, and the combustion reaction will become easy. At the same time, the CO share in the combustion gases is more and more less,the CO2 share is more and more larger,the fuel's burnout rate is be increased.%利用TG-FTIR对生物质、煤及其混合物的燃烧过程及燃烧产物进行分析,研究了生物质添加比例、升温速率、氧气浓度对燃烧过程的影响.结果表明,生物质的加入可以有效改善样品的燃烧性能,提高样品的燃尽性能.提高生物质添加比例,可以降低燃烧气态产物中CO与CO2的比例,提高燃料利用率.提高升温速率和氧气浓度,可以提高生物质与煤混合物的燃烧速度,缩短燃烧时间,改善生物质与煤混合物的燃烧性能,有利于燃烧反应的进行;同时,燃烧气态产物中CO所占比例逐渐减小,CO2所占比例逐渐增大,提高了燃料的燃尽率.

  5. Biomass - Overview of Swiss Research Programme 2003; Biomasse

    Energy Technology Data Exchange (ETDEWEB)

    Binggeli, D.; Guggisberg, B.

    2003-07-01

    This overview for the Swiss Federal Office of Energy (SFOE) discusses the results obtained in 2003 in various research projects worked on in Switzerland on the subject of biomass. In the biomass combustion area, subjects discussed include system optimisation for automatic firing, combustion particles, low-particle pellet furnaces, design and optimisation of wood-fired storage ovens, efficiency of filtering techniques and methane generation from wood. Also, an accredited testing centre for wood furnaces is mentioned and measurements made on an installation are presented. As far as the fermentation of biogenic wastes is concerned, biogas production from dairy-product wastes is described. Other projects discussed include a study on eco-balances of energy products, certification and marketing of biogas, evaluation of membranes, a measurement campaign for solar sludge-drying, the operation of a percolator installation for the treatment of bio-wastes, the effects of compost on the environment and the fermentation of coffee wastes. Also, statistics on biogas production in 2002 is looked at. Finally, a preliminary study on biofuels is presented.

  6. Characterization and quantification of deposits build up and removal in straw suspension fired boilers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Arendt Jensen, Peter; Wedel, S.; Jappe Frandsen, F.; Dam-Johansen, K.; Shafique Bashir, M. [Technical Univ. of Denmark. CHEC Research Centre, Kgs. Lyngby (Denmark); Wadenback, J.; Thaaning Pedersen, S. [Vattenfall A/S, Copenhagen (Denmark)

    2013-07-15

    This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed by conducting advanced probe measurements at the Amagervaerkets Vattenfall owed boilers. It was the objective of the project to provide an improved understanding of ash deposit formation and removal in biomass suspension fired boilers. The project have provided a large amount of knowledge on the following issues: 1) The influence of local boiler conditions on deposit formation in suspension fired boilers using wood or co-firing straw and wood, 2) quantification of deposit removal in biomass suspension firing boilers with regards both to natural shedding and soot blower induced shedding, 3) established relations of the properties of fuel ash, fly ash and deposits, 4) use of coal ash to remedy biomass ash induced boiler deposit problems. (Author)

  7. Biomass torrefaction mill

    Science.gov (United States)

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  8. Developing Biomass Equations for Western Hemlock and Red Alder Trees in Western Oregon Forests

    OpenAIRE

    Krishna P Poudel; Hailemariam Temesgen

    2016-01-01

    Biomass estimates are required for reporting carbon, assessing feedstock availability, and assessing forest fire threat. We developed diameter- and height-based biomass equations for Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and red alder (Alnus rubra Bong.) trees in Western Oregon. A system of component biomass equations was fitted simultaneously with a constrained seemingly unrelated regression. Additionally, a linear model that predicts total aboveground biomass as a function of DB...

  9. Fire Protection for Buildings

    Science.gov (United States)

    Edmunds, Jane

    1972-01-01

    Reviews attack on fire safety in high rise buildings made by a group of experts representing the iron and steel industry at a recent conference. According to one expert, fire problems are people oriented, which calls for emphasis on fire prevention rather than reliance on fire suppression and for fire pretection to be built into a structure.…

  10. A Second-order Impact Model for Forest Fire Regimes

    OpenAIRE

    Maggi, S. (Stefania); Rinaldi, S

    2006-01-01

    We present a very simple "impact" model for the description of forest fires and show that it can mimic the known characteristics of wild fire regimes in savannas, boreal forests, and Mediterranean forests. Moreover, the distribution of burned biomasses in model generated fires resemble those of burned areas in numerous large forests around the world. The model has also the merits of being the first second-order model for forest fires and the first example of the use of impact models in the st...

  11. A second-order impact model for forest fire regimes.

    Science.gov (United States)

    Maggi, Stefano; Rinaldi, Sergio

    2006-09-01

    We present a very simple "impact" model for the description of forest fires and show that it can mimic the known characteristics of wild fire regimes in savannas, boreal forests, and Mediterranean forests. Moreover, the distribution of burned biomasses in model generated fires resemble those of burned areas in numerous large forests around the world. The model has also the merits of being the first second-order model for forest fires and the first example of the use of impact models in the study of ecosystems. PMID:16723147

  12. Energy from Biomass for Conversion of Biomass

    Science.gov (United States)

    Abolins, J.; Gravitis, J.

    2009-01-01

    Along with estimates of minimum energy required by steam explosion pre-treatment of biomass some general problems concerning biomass conversion into chemicals, materials, and fuels are discussed. The energy necessary for processing biomass by steam explosion auto-hydrolysis is compared with the heat content of wood and calculated in terms of the amount of saturated steam consumed per unit mass of the dry content of wood biomass. The fraction of processed biomass available for conversion after steam explosion pre-treatment is presented as function of the amount of steam consumed per unit mass of the dry content of wood. The estimates based on a simple model of energy flows show the energy required by steam explosion pre-treatment of biomass being within 10% of the heat content of biomass - a realistic amount demonstrating that energy for the process can be supplied from a reasonable proportion of biomass used as the source of energy for steam explosion pre-treatment.

  13. Abrupt fire regime change may cause landscape-wide loss of mature obligate seeder forests.

    Science.gov (United States)

    Bowman, David M J S; Murphy, Brett P; Neyland, Dominic L J; Williamson, Grant J; Prior, Lynda D

    2014-03-01

    Obligate seeder trees requiring high-severity fires to regenerate may be vulnerable to population collapse if fire frequency increases abruptly. We tested this proposition using a long-lived obligate seeding forest tree, alpine ash (Eucalyptus delegatensis), in the Australian Alps. Since 2002, 85% of the Alps bioregion has been burnt by several very large fires, tracking the regional trend of more frequent extreme fire weather. High-severity fires removed 25% of aboveground tree biomass, and switched fuel arrays from low loads of herbaceous and litter fuels to high loads of flammable shrubs and juvenile trees, priming regenerating stands for subsequent fires. Single high-severity fires caused adult mortality and triggered mass regeneration, but a second fire in quick succession killed 97% of the regenerating alpine ash. Our results indicate that without interventions to reduce fire severity, interactions between flammability of regenerating stands and increased extreme fire weather will eliminate much of the remaining mature alpine ash forest. PMID:24132866

  14. Fiber Bragg Grating Sensors for Harsh Environments

    Directory of Open Access Journals (Sweden)

    Stephen J. Mihailov

    2012-02-01

    Full Text Available Because of their small size, passive nature, immunity to electromagnetic interference, and capability to directly measure physical parameters such as temperature and strain, fiber Bragg grating sensors have developed beyond a laboratory curiosity and are becoming a mainstream sensing technology. Recently, high temperature stable gratings based on regeneration techniques and femtosecond infrared laser processing have shown promise for use in extreme environments such as high temperature, pressure or ionizing radiation. Such gratings are ideally suited for energy production applications where there is a requirement for advanced energy system instrumentation and controls that are operable in harsh environments. This paper will present a review of some of the more recent developments.

  15. Thermal annealing of tilted fiber Bragg gratings

    Science.gov (United States)

    González-Vila, Á.; Rodríguez-Cobo, L.; Mégret, P.; Caucheteur, C.; López-Higuera, J. M.

    2016-05-01

    We report a practical study of the thermal decay of cladding mode resonances in tilted fiber Bragg gratings, establishing an analogy with the "power law" evolution previously observed on uniform gratings. We examine how this process contributes to a great thermal stability, even improving it by means of a second cycle slightly increasing the annealing temperature. In addition, we show an improvement of the grating spectrum after annealing, with respect to the one just after inscription, which suggests the application of this method to be employed to improve saturation issues during the photo-inscription process.

  16. An electromagnetically induced grating by microwave modulation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Zhi-Hong; Shin, Sung Guk; Kim, Kisik, E-mail: kisik@inha.ac.k [Department of Physics, Inha University, Incheon 402-751 (Korea, Republic of)

    2010-08-28

    We study the phenomenon of an electromagnetically induced phase grating in a double-dark state system of {sup 87}Rb atoms, the two closely placed lower fold levels of which are coupled by a weak microwave field. Owing to the existence of the weak microwave field, the efficiency of the phase grating is strikingly improved, and an efficiency of approximately 33% can be achieved. Under the action of the weak standing wave field, the high efficiency of the phase grating can be maintained by modulating the strength and detuning of the weak microwave field, increasing the strength of the standing wave field. (fast track communication)

  17. Diffraction by m-bonacci gratings

    Science.gov (United States)

    Monsoriu, Juan A.; Giménez, Marcos H.; Furlan, Walter D.; Barreiro, Juan C.; Saavedra, Genaro

    2015-11-01

    We present a simple diffraction experiment with m-bonacci gratings as a new interesting generalization of the Fibonacci ones. Diffraction by these non-conventional structures is proposed as a motivational strategy to introduce students to basic research activities. The Fraunhofer diffraction patterns are obtained with the standard equipment present in most undergraduate physics labs and are compared with those obtained with regular periodic gratings. We show that m-bonacci gratings produce discrete Fraunhofer patterns characterized by a set of diffraction peaks which positions are related to the concept of a generalized golden mean. A very good agreement is obtained between experimental and numerical results and the students’ feedback is discussed.

  18. [Effects of fire recurrence on fire behaviour in cork oak woodlands (Quercus suber L.) and Mediterranean shrublands over the last fifty years].

    Science.gov (United States)

    Schaffhauser, Alice; Pimont, François; Curt, Thomas; Cassagne, Nathalie; Dupuy, Jean-Luc; Tatoni, Thierry

    2015-12-01

    Past fire recurrence impacts the vegetation structure, and it is consequently hypothesized to alter its future fire behaviour. We examined the fire behaviour in shrubland-forest mosaics of southeastern France, which were organized along a range of fire frequency (0 to 3-4 fires along the past 50 years) and had different time intervals between fires. The mosaic was dominated by Quercus suber L. and Erica-Cistus shrubland communities. We described the vegetation structure through measurements of tree height, base of tree crown or shrub layer, mean diameter, cover, plant water content and bulk density. We used the physical model Firetec to simulate the fire behaviour. Fire intensity, fire spread, plant water content and biomass loss varied significantly according to fire recurrence and vegetation structure, mainly linked to the time since the last fire, then the number of fires. These results confirm that past fire recurrence affects future fire behaviour, with multi-layered vegetation (particularly high shrublands) producing more intense fires, contrary to submature Quercus woodlands that have not burnt since 1959 and that are unlikely to reburn. Further simulations, with more vegetation scenes according to shrub and canopy covers, will complete this study in order to discuss the fire propagation risk in heterogeneous vegetation, particularly in the Mediterranean area, with a view to a local management of these ecosystems.

  19. Influence of grating thickness in low-contrast subwavelength grating concentrating lenses

    Science.gov (United States)

    Ye, Mao; Yi, Ya Sha

    2016-07-01

    Conventional subwavelength grating concentrating lenses are designed based on calculated phase overlap, wherein the phase change is fixed by the grating thickness, bar-width, and airgap, and therefore the focus. We found that certain concentration effects can still be maintained by changing the grating thickness with the same bar-widths and airgap dimensions. Following that, we discovered the existence of the grating thickness threshold; light concentration intensity spikes upon exceeding this limit. However, the light concentration property does not change continuously with respect to a steady increase in grating thickness. This observation indicates that there exists a concentration mode self-interference effect along the light propagation direction inside the gratings. Our results may provide guidance in designing and fabricating microlenses in a potentially more easy and controllable manner. Such approaches can be utilized in various integrated nanophotonics applications ranging from optical cavities and read/write heads to concentrating photovoltaics.

  20. Advanced experimental applications for x-ray transmission gratings Spectroscopy using a novel grating fabrication method

    CERN Document Server

    Hurvitz, G; Strum, G; Shpilman, Z; Levy, I; Fraenkel, M

    2012-01-01

    A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses Focused-Ion-Beam (FIB) technology to fabricate high-quality free standing grating bars on Transmission Electron Microscopy grids (TEM-grid). High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range. Double grating combinations of identical or different parameters are easily fabricated, allowing advanced one-shot application of transmission grating spectroscopy. These applications include spectroscopy with different spectral resolutions, bandwidths, dynamic ranges, and may serve for identification of high-order contribution, and spectral calibrations of various x-ray optical elements.

  1. Advanced experimental applications for x-ray transmission gratings spectroscopy using a novel grating fabrication method

    Science.gov (United States)

    Hurvitz, G.; Ehrlich, Y.; Strum, G.; Shpilman, Z.; Levy, I.; Fraenkel, M.

    2012-08-01

    A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses focused-ion-beam technology to fabricate high-quality free standing grating bars on transmission electron microscopy grids. High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range. Double grating combinations of identical or different parameters are easily fabricated, allowing advanced one-shot application of transmission grating spectroscopy. These applications include spectroscopy with different spectral resolutions, bandwidths, dynamic ranges, and may serve for identification of high-order contribution, and spectral calibrations of various x-ray optical elements.

  2. Release of Corrosive Species above the Grate in a Waste Boiler and the Implication for Improved Electrical Efficiency

    DEFF Research Database (Denmark)

    Bøjer, Martin; Jensen, Peter Arendt; Dam-Johansen, Kim;

    2010-01-01

    A relatively low electrical efficiency of 20−25% is obtained in typical west European waste boilers. Ash species released from the grate combustion zone form boiler deposits with high concentrations of Cl, Na, K, Zn, Pb, and S that cause corrosion of superheater tubes at high temperature...... that the waste grate combustion process can provide a flue gas with a high energy content and a relatively low concentration of corrosive species. This opens up for the possibility of using an additional superheater section to increase the steam temperature and, thereby, increase electrical efficiency........ The superheater steam temperature has to be limited to around 425 °C, and thereby, the electrical efficiency remains low compared to wood or coal-fired boilers. If a separate part of the flue gas from the grate has a low content of corrosive species, it may be used to superheat steam to a higher temperature...

  3. Relationships between annual plant productivity, nitrogen deposition and fire size in low-elevation California desert scrub

    Science.gov (United States)

    Rao, Leela E.; Matchett, John R.; Brooks, Matthew L.; Johns, Robert; Minnich, Richard A.; Allen, Edith B.

    2014-01-01

    Although precipitation is correlated with fire size in desert ecosystems and is typically used as an indirect surrogate for fine fuel load, a direct link between fine fuel biomass and fire size has not been established. In addition, nitrogen (N) deposition can affect fire risk through its fertilisation effect on fine fuel production. In this study, we examine the relationships between fire size and precipitation, N deposition and biomass with emphasis on identifying biomass and N deposition thresholds associated with fire spreading across the landscape. We used a 28-year fire record of 582 burns from low-elevation desert scrub to evaluate the relationship of precipitation, N deposition and biomass with the distribution of fire sizes using quantile regression. We found that models using annual biomass have similar predictive ability to those using precipitation and N deposition at the lower to intermediate portions of the fire size distribution. No distinct biomass threshold was found, although within the 99th percentile of the distribution fire size increased with greater than 125 g m–2 of winter fine fuel production. The study did not produce an N deposition threshold, but did validate the value of 125 g m–2 of fine fuel for spread of fires.

  4. Numerical investigation of ash deposition in straw-fired boilers

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    accumulation rates encountered during straw combustion in grate-fired boilers. The sub-models have been based on information about the combustion and deposition properties of straw gathered from the literature and combined into a single Computational Fluid Dynamics (CFD) based analysis tool which can aid...... in the design phase of straw-fired boilers. Some of the primary model outputs include improved heat transfer rate predictions and detailed information about local deposit formation rates. This information is essential when boiler availability and efficiency is to be estimated. A stand-alone program has been...... developed to predict the combustion processes on the grate and the release rate of KCl vapor. These outputs form the boundary conditions for the CFD analysis. The bed model has been validated through comparison with experimental data obtained during batch combustion of straw. It was found that the heat...

  5. 循环流化床锅炉生物质与煤混烧积灰腐蚀试验%Experimental study on ash deposition and corrosion in a CFB boiler co-firing biomass with coal

    Institute of Scientific and Technical Information of China (English)

    刘志; 雷秀坚; 汪佩宁; 胡康涛; 杨海瑞

    2015-01-01

    During ash decomposition and corrosion tests in a 75 t/h circulating fluidized bed (CFB)boiler burning coal and biomass,the corrosion probe equipped with three kinds of metal samples was placed in front of the superheater,and the superheater tube wall temperature was simulated with a system of air cooling.Three kinds of metal deposition samples were obtained in operating mode (duration time of 24 hours)with three mixing ratios of coal and biomass.The physicochemical property of the samples was ana-lyzed by SEM-EDX.The results show that,under the testing conditions,no deposition was found at the wind side,and the deposition formed at the lee side was different for different metallic materials.No materi-al loss or significant corrosion was detected.It is proved in this study that depositions at the lee side of the superheater were probably more serious than that at the wind side,and the co-combustion of coal and bio-mass containing low levels of alkali metal will not cause serious deposition or corrosion and can be applied in industrial production.%将3种不同金属管材样品环的气冷腐蚀探头置于某生物质与煤混烧的75 t/h 循环流化床(CFB)锅炉尾部烟道低温过热器前,通过空气冷却模拟过热器的管壁温度,获得3种混烧比例工况下(持续时间24 h)3种管材的积灰样品。利用扫描电子显微镜分析积灰的理化特性,探讨混烧比例和材料种类对积灰腐蚀的影响规律。结果表明:在测试工况下,样品环迎风面不存在明显积灰现象,而背风面积灰明显,且随着材料的不同而有所不同,但未发现明显腐蚀或金属磨损,表明碱金属含量相对较低的生物质与煤混烧并不会造成严重积灰及腐蚀。

  6. Comparison of the Hazard Mapping System (HMS) fire product to ground-based fire records in Georgia, USA

    Science.gov (United States)

    Hu, Xuefei; Yu, Chao; Tian, Di; Ruminski, Mark; Robertson, Kevin; Waller, Lance A.; Liu, Yang

    2016-03-01

    Biomass burning has a significant and adverse impact on air quality, climate change, and various ecosystems. The Hazard Mapping System (HMS) detects fires using data from multiple satellite sensors in order to maximize its fire detection rate. However, to date, the detection rate of the HMS fire product for small fires has not been well studied, especially using ground-based fire records. This paper utilizes the 2011 fire information compiled from ground observations and burn authorizations in Georgia to assess the comprehensiveness of the HMS active fire product. The results show that detection rates of the hybrid HMS increase substantially by integrating multiple satellite instruments. The detection rate increases dramatically from 3% to 80% with an increase in fire size from less than 0.02 km2 to larger than 2 km2, resulting in detection of approximately 12% of all recorded fires which represent approximately 57% of the total area burned. The spatial pattern of detection rates reveals that grid cells with high detection rates are generally located in areas where large fires occur frequently. The seasonal analysis shows that overall detection rates in winter and spring (12% and 13%, respectively) are higher than those in summer and fall (3% and 6%, respectively), mainly because of higher percentages of large fires (>0.19 km2) that occurred in winter and spring. The land cover analysis shows that detection rates are 2-7 percentage points higher in land cover types that are prone to large fires such as forestland and shrub land.

  7. Fabrication update on critical-angle transmission gratings for soft x-ray grating spectrometers

    Science.gov (United States)

    Heilmann, Ralf K.; Bruccoleri, Alex; Mukherjee, Pran; Yam, Jonathan; Schattenburg, Mark L.

    2011-09-01

    Diffraction grating-based, wavelength dispersive high-resolution soft x-ray spectroscopy of celestial sources promises to reveal crucial data for the study of the Warm-Hot Intergalactic Medium, the Interstellar Medium, warm absorption and outflows in Active Galactic Nuclei, coronal emission from stars, and other areas of interest to the astrophysics community. Our recently developed critical-angle transmission (CAT) gratings combine the advantages of the Chandra high and medium energy transmission gratings (low mass, high tolerance of misalignments and figure errors, polarization insensitivity) with those of blazed reflection gratings (high broad band diffraction efficiency, high resolution through use of higher diffraction orders) such as the ones on XMM-Newton. Extensive instrument and system configuration studies have shown that a CAT grating-based spectrometer is an outstanding instrument capable of delivering resolving power on the order of 5,000 and high effective area, even with a telescope point-spread function on the order of many arc-seconds. We have fabricated freestanding, ultra-high aspect-ratio CAT grating bars from silicon-on-insulator wafers using both wet and dry etch processes. The 200 nm-period grating bars are supported by an integrated Level 1 support mesh, and a coarser external Level 2 support mesh. The resulting grating membrane is mounted to a frame, resulting in a grating facet. Many such facets comprise a grating array that provides light-weight coverage of large-area telescope apertures. Here we present fabrication results on the integration of CAT gratings and the different high-throughput support mesh levels and on membrane-frame bonding. We also summarize recent x-ray data analysis of 3 and 6 micron deep wet-etched CAT grating prototypes.

  8. Silicon waveguide polarization rotation Bragg grating with phase shift section and sampled grating scheme

    Science.gov (United States)

    Okayama, Hideaki; Onawa, Yosuke; Shimura, Daisuke; Yaegashi, Hiroki; Sasaki, Hironori

    2016-08-01

    We describe a Bragg grating with a phase shift section and a sampled grating scheme that converts input polarization to orthogonal polarization. A very narrow polarization-independent wavelength peak can be generated by phase shift structures and polarization-independent multiple diffraction peaks by sampled gratings. The characteristics of the device were examined by transfer matrix and finite-difference time-domain methods.

  9. Fuel consumption and fire emissions estimates using Fire Radiative Power, burned area and statistical modelling on the fire event scale

    Science.gov (United States)

    Ruecker, Gernot; Leimbach, David; Guenther, Felix; Barradas, Carol; Hoffmann, Anja

    2016-04-01

    Fire Radiative Power (FRP) retrieved by infrared sensors, such as flown on several polar orbiting and geostationary satellites, has been shown to be proportional to fuel consumption rates in vegetation fires, and hence the total radiative energy released by a fire (Fire Radiative Energy, FRE) is proportional to the total amount of biomass burned. However, due to the sparse temporal coverage of polar orbiting and the coarse spatial resolution of geostationary sensors, it is difficult to estimate fuel consumption for single fire events. Here we explore an approach for estimating FRE through temporal integration of MODIS FRP retrievals over MODIS-derived burned areas. Temporal integration is aided by statistical modelling to estimate missing observations using a generalized additive model (GAM) and taking advantage of additional information such as land cover and a global dataset of the Canadian Fire Weather Index (FWI), as well as diurnal and annual FRP fluctuation patterns. Based on results from study areas located in savannah regions of Southern and Eastern Africa and Brazil, we compare this method to estimates based on simple temporal integration of FRP retrievals over the fire lifetime, and estimate the potential variability of FRP integration results across a range of fire sizes. We compare FRE-based fuel consumption against a database of field experiments in similar landscapes. Results show that for larger fires, this method yields realistic estimates and is more robust when only a small number of observations is available than the simple temporal integration. Finally, we offer an outlook on the integration of data from other satellites, specifically FireBird, S-NPP VIIRS and Sentinel-3, as well as on using higher resolution burned area data sets derived from Landsat and similar sensors.

  10. Soil properties and root biomass responses to prescribed burning in young corsican pine (Pinus nigra Arn.) stands

    OpenAIRE

    Tüfekçioğlu, Aydın; Küçük, Mehmet; Sağlam, Bülent; Bilgili, Ertuğrul; Altun, Lokman

    2009-01-01

    Fire is an important tool in the management of forest ecosystems. Although both prescribed and wildland fires are common in Turkey, few studies have addressed the influence of such disturbances on soil properties and root biomass dynamics. In this study, soil properties and root biomass responses to prescribed fire were investigated in 25-year-old corsican pine (Pinus nigra Arn.) stands in Kastamonu, Turkey. The standswere established byplanting and were subjected to prescribed burning in Jul...

  11. Access Platforms for Offshore Wind Turbines Using Gratings

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Rasmussen, Michael R.

    2008-01-01

    The paper deals with forces generated by a stationary jet on different types of gratings and a solid plate. The force reduction factors for the different gratings compared to the solid plate mainly depend on the porosity of the gratings, but the geometry of the grating is also of some importance........ The derived reduction factors are expected to be applicable to design of offshore wind turbine access platforms with gratings where slamming also is an important factor....

  12. Long period fiber gratings induced by mechanical resonance

    CERN Document Server

    Shahal, Shir; Duadi, Hamootal; Fridman, Moti

    2015-01-01

    We present a simple, and robust method for writing long period fiber gratings with low polarization dependent losses. Our method is based on utilizing mechanical vibrations of the tapered fiber while pooling it. Our method enables real-time tunability of the periodicity, efficiency and length of the grating. We also demonstrate complex grating by writing multiple gratings simultaneously. Finally, we utilized the formation of the gratings in different fiber diameters to investigate the Young's modulus of the fiber.

  13. Fire safety at home

    Science.gov (United States)

    ... over the smoke alarm as needed. Using a fire extinguisher can put out a small fire to keep it from getting out of control. Tips for use include: Keep fire extinguishers in handy locations, at least one on ...

  14. Fire Ant Bites

    Science.gov (United States)

    ... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...

  15. Crown Fire Potential

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...

  16. Fire in ice: two millennia of boreal forest fire history from the Greenland NEEM ice core

    Science.gov (United States)

    Zennaro, P.; Kehrwald, N.; McConnell, J. R.; Schüpbach, S.; Maselli, O. J.; Marlon, J.; Vallelonga, P.; Leuenberger, D.; Zangrando, R.; Spolaor, A.; Borrotti, M.; Barbaro, E.; Gambaro, A.; Barbante, C.

    2014-10-01

    Biomass burning is a major source of greenhouse gases and influences regional to global climate. Pre-industrial fire-history records from black carbon, charcoal and other proxies provide baseline estimates of biomass burning at local to global scales spanning millennia, and are thus useful to examine the role of fire in the carbon cycle and climate system. Here we use the specific biomarker levoglucosan together with black carbon and ammonium concentrations from the North Greenland Eemian (NEEM) ice cores (77.49° N, 51.2° W; 2480 m a.s.l) over the past 2000 years to infer changes in boreal fire activity. Increases in boreal fire activity over the periods 1000-1300 CE and decreases during 700-900 CE coincide with high-latitude NH temperature changes. Levoglucosan concentrations in the NEEM ice cores peak between 1500 and 1700 CE, and most levoglucosan spikes coincide with the most extensive central and northern Asian droughts of the past millennium. Many of these multi-annual droughts are caused by Asian monsoon failures, thus suggesting a connection between low- and high-latitude climate processes. North America is a primary source of biomass burning aerosols due to its relative proximity to the Greenland Ice Cap. During major fire events, however, isotopic analyses of dust, back trajectories and links with levoglucosan peaks and regional drought reconstructions suggest that Siberia is also an important source of pyrogenic aerosols to Greenland.

  17. Theory of photorefractive dynamic grating formulation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The photorefractive holographic recording and two-beam coupling are both dynamic grating formulation process. The interference light intensity of the two coherent beams induces a phase grating though photo-induced refractive index variation and the phase grating changing the intensities of the two beams through beam-coupling take place at the same time. By solving simultaneously the band transport equations and wave-coupled equations, and using the light intensity modulation as the main variable, the analytic solution is obtained, which is valid for any light intensity modulation and constant light excitation efficiency. Here all the mechanics of drift, diffusion and photovoltaic effect are considered. The result shows that the modulation of the dynamic grating varies more slowly compared with that of the linear modulation approximation.

  18. Eco-hydrology driven fire regime in savanna.

    Science.gov (United States)

    Ursino, Nadia

    2014-08-21

    Fire is an important evolutionary force and ecosystem consumer that shapes savanna composition. However, ecologists have not comprehensively explained the functioning and maintenance of flammable savannas. A new minimal model accounting for the interdependence between soil saturation, biomass growth, fuel availability and fire has been used to predict the increasing tree density and fire frequency along a Mean Annual Rainfall (MAR) gradient for a typical savanna. Cyclic fire recurrence is reproduced using a predator prey approach in which fire is the "predator" and vegetation is the "prey". For the first time, fire frequency is not defined a priori but rather arises from the composition of vegetation, which determines fuel availability and water limitation. Soil aridity affects fuel production and fuel composition, thus indirectly affecting the ecosystem vulnerability to fire and fire frequency. The model demonstrates that two distinct eco-hydrological states correspond to different fire frequencies: (i) at low MAR, grass is abundant and the impact of fire on the environment is enhanced by the large fuel availability, (ii) at higher MAR, tree density progressively increases and provides less fuel for fire, leading to more frequent and less destructive fires, and (iii) the threshold MAR that determines the transition between the two states and the fire frequency at high MAR are affected by the vulnerability of trees to grass fire. The eco-hydrology-driven predator-prey model originally predicts that the transition between dry and wet savanna is characterized by a shift in wildfire frequency driven by major differences in soil moisture available for plants and savanna structure. The shift and the role of fire in conserving savanna ecosystems could not have been predicted if fire was considered as an external forcing rather than an intrinsic property of the ecosystem.

  19. Travel Guide (Travelling Fires)

    OpenAIRE

    Stern-Gottfried, Jamie; Rein, Guillermo; Torero, Jose L

    2009-01-01

    Close inspection of real fires in large, open compartments reveals that they do not burn simultaneously throughout the whole compartment. Instead, these fires tend to move as flames spread, partitions or false ceilings break, and ventilation changes through glazing failure. These fires have been labelled ‘travelling fires’ and represent a new understanding of fire behaviour in modern building layouts. Despite these observations, fire scenarios currently used for the structural fire design of ...

  20. Hydraulic Capacity of an ADA Compliant Street Drain Grate

    Energy Technology Data Exchange (ETDEWEB)

    Lottes, Steven A. [Argonne National Lab. (ANL), Argonne, IL (United States); Bojanowski, Cezary [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    Resurfacing of urban roads with concurrent repairs and replacement of sections of curb and sidewalk may require pedestrian ramps that are compliant with the American Disabilities Act (ADA), and when street drains are in close proximity to the walkway, ADA compliant street grates may also be required. The Minnesota Department of Transportation ADA Operations Unit identified a foundry with an available grate that meets ADA requirements. Argonne National Laboratory’s Transportation Research and Analysis Computing Center used full scale three dimensional computational fluid dynamics to determine the performance of the ADA compliant grate and compared it to that of a standard vane grate. Analysis of a parametric set of cases was carried out, including variation in longitudinal, gutter, and cross street slopes and the water spread from the curb. The performance of the grates was characterized by the fraction of the total volume flow approaching the grate from the upstream that was captured by the grate and diverted into the catch basin. The fraction of the total flow entering over the grate from the side and the fraction of flow directly over a grate diverted into the catch basin were also quantities of interest that aid in understanding the differences in performance of the grates. The ADA compliant grate performance lagged that of the vane grate, increasingly so as upstream Reynolds number increased. The major factor leading to the performance difference between the two grates was the fraction of flow directly over the grates that is captured by the grates.

  1. Fire Models and Design Fires

    DEFF Research Database (Denmark)

    Poulsen, Annemarie

    The aim of this project is to perform an experimental study on the influence of the thermal feedback on the burning behavior of well ventilated pre-flashover fires. For the purpose an experimental method has been developed. Here the same identical objects are tested under free burn conditions...... be lost through the boundaries. The increase of the heat release rate after the onset of thermal feedback did not seem to be dominated by either temperature of the smoke layer/enclosure boundaries or the type of materials of the burning object. The onset point of thermal runaway was found to depend...

  2. Impact of biomass burning on the atmosphere

    International Nuclear Information System (INIS)

    Fire has played an important part in biogeochemical cycling throughout most of the history of our planet. Ice core studies have been very beneficial in paleoclimate studies and constraining the budgets of biogeochemical cycles through the past 160,000 years of the Vostok ice core. Although to date there has been no way of determining cause and effect, concentration of greenhouse gases directly correlates with temperature in ice core analyses. Recent ice core studies on Greenland have shown that significant climate change can be very rapid on the order of a decade. This chapter addresses the coupled evolution of our planet's atmospheric composition and biomass burning. Special attention is paid to the chemical and climatic impacts of biomass burning on the atmosphere throughout the last century, specifically looking at the cycles of carbon, nitrogen, and sulfur. Information from ice core measurements may be useful in understanding the history of fire and its historic affect on the composition of the atmosphere and climate

  3. Sampled phase-shift fiber Bragg gratings

    Institute of Scientific and Technical Information of China (English)

    Xu Wang(王旭); Chongxiu Yu(余重秀); Zhihui Yu(于志辉); Qiang Wu(吴强)

    2004-01-01

    A phase-shift fiber Bragg grating (FBG) with sampling is proposed to generate a multi-channel bandpass filter in the background of multi-channel stopbands. The sampled noire fiber gratings are analyzed by Fourier transform theory first, and then simulation and experiment are performed, the results show that transmission peaks are opened in every reflective channel, the spectrum shape of every channel is identical.It can be used to fabricate multi-wavelength distributed feedback (DFB) fiber laser.

  4. Spatial patterns of large natural fires in Sierra Nevada wilderness areas

    Science.gov (United States)

    Collins, B.M.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

    2007-01-01

    The effects of fire on vegetation vary based on the properties and amount of existing biomass (or fuel) in a forest stand, weather conditions, and topography. Identifying controls over the spatial patterning of fire-induced vegetation change, or fire severity, is critical in understanding fire as a landscape scale process. We use gridded estimates of fire severity, derived from Landsat ETM+ imagery, to identify the biotic and abiotic factors contributing to the observed spatial patterns of fire severity in two large natural fires. Regression tree analysis indicates the importance of weather, topography, and vegetation variables in explaining fire severity patterns between the two fires. Relative humidity explained the highest proportion of total sum of squares throughout the Hoover fire (Yosemite National Park, 2001). The lowest fire severity corresponded with increased relative humidity. For the Williams fire (Sequoia/Kings Canyon National Parks, 2003) dominant vegetation type explains the highest proportion of sum of squares. Dominant vegetation was also important in determining fire severity throughout the Hoover fire. In both fires, forest stands that were dominated by lodgepole pine (Pinus contorta) burned at highest severity, while red fir (Abies magnifica) stands corresponded with the lowest fire severities. There was evidence in both fires that lower wind speed corresponded with higher fire severity, although the highest fire severity in the Williams fire occurred during increased wind speed. Additionally, in the vegetation types that were associated with lower severity, burn severity was lowest when the time since last fire was fewer than 11 and 17 years for the Williams and Hoover fires, respectively. Based on the factors and patterns identified, managers can anticipate the effects of management ignited and naturally ignited fires at the forest stand and the landscape levels. ?? 2007 Springer Science+Business Media, Inc.

  5. Dynamic optical coupled system employing Dammann gratings

    Science.gov (United States)

    Di, Caihui; Zhou, Changhe; Ru, Huayi

    2004-10-01

    With the increasing of the number of users in optical fiber communications, fiber-to-home project has a larger market value. Then the need of dynamic optical couplers, especially of N broad-band couplers, becomes greater. Though some advanced fiber fusion techniques have been developed, they still have many shortcomings. In this paper we propose a dynamic optical coupled system employing even-numbered Dammann gratings, which have the characteristic that the phase distribution in the first half-period accurately equals to that in the second-period with π phase inversion. In our experiment, we divide a conventional even-numbered Dammann grating into two identical gratings. The system can achieve the beam splitter and combiner as the switch between them according to the relative shift between two complementary gratings. When there is no shift between the gratings, the demonstrated 1×8 dynamic optical coupler achieves good uniformity of 0.06 and insertion loss of around 10.8 dB for each channel as a splitter. When the two gratings have an accurate shift of a half-period between them, our system has a low insertion loss of 0.46 dB as a combiner at a wavelength of 1550 nm.

  6. RDF co-firing demonstration project at the Enel Fusina power plant

    Energy Technology Data Exchange (ETDEWEB)

    Gasperetti, Silvia; Leoni, Paolo; Rossi, Nicola [Enel Engineering and Research, Pisa (Italy); Di Giovanni, Angelo; Bassi, Fausto; Pavanetto, Stefano [Enel Generation and Energy Management, Venezia (Italy); Fantini, Vincenzo; Cavaliere, Angelo [RSE, Milano (Italy). Power Generation System Dept.

    2013-06-01

    ENEL carried out demonstration activities at the Fusina power plant aimed at proving the feasibility of RDF (Refuse Derived Fuel)/coal co-firing. Since 2004, smaller amounts of RDF have been co-fired with coal in two 320 MWe boilers. Since February 2009, the average RDF share has been increased up to 5 % on thermal input for each unit at full load. Between 2008 to 2012, the Fusina power plant was involved in the EU-funded DEBCO (Demonstration of Biomass Co-firing) project, which focused on the demonstration of large-scale biomass or RDF co-firing and supply chain integration. (orig.)

  7. Fire in ice: two millennia of Northern Hemisphere fire history from the Greenland NEEM ice core

    Directory of Open Access Journals (Sweden)

    P. Zennaro

    2014-02-01

    Full Text Available Biomass burning is a major source of greenhouse gases and influences regional to global climate. Pre-industrial fire-history records from black carbon, charcoal and other proxies provide baseline estimates of biomass burning at local to global scales, but there remains a need for broad-scale fire proxies that span millennia in order to understand the role of fire in the carbon cycle and climate system. We use the specific biomarker levoglucosan, and multi-source black carbon and ammonium concentrations to reconstruct fire activity from the North Greenland Eemian (NEEM ice cores (77.49° N; 51.2° W, 2480 m a.s.l. over the past 2000 years. Increases in boreal fire activity (1000–1300 CE and 1500–1700 CE over multi-decadal timescales coincide with the most extensive central and northern Asian droughts of the past two millennia. The NEEM biomass burning tracers coincide with temperature changes throughout much of the past 2000 years except for during the extreme droughts, when precipitation changes are the dominant factor. Many of these multi-annual droughts are caused by monsoon failures, thus suggesting a connection between low and high latitude climate processes. North America is a primary source of biomass burning aerosols due to its relative proximity to the NEEM camp. During major fire events, however, isotopic analyses of dust, back-trajectories and links with levoglucosan peaks and regional drought reconstructions suggest that Siberia is also an important source of pyrogenic aerosols to Greenland.

  8. Biomass treatment method

    Science.gov (United States)

    Friend, Julie; Elander, Richard T.; Tucker, III; Melvin P.; Lyons, Robert C.

    2010-10-26

    A method for treating biomass was developed that uses an apparatus which moves a biomass and dilute aqueous ammonia mixture through reaction chambers without compaction. The apparatus moves the biomass using a non-compressing piston. The resulting treated biomass is saccharified to produce fermentable sugars.

  9. The status and challenge of global fire modelling

    Science.gov (United States)

    Hantson, Stijn; Arneth, Almut; Harrison, Sandy P.; Kelley, Douglas I.; Prentice, I. Colin; Rabin, Sam S.; Archibald, Sally; Mouillot, Florent; Arnold, Steve R.; Artaxo, Paulo; Bachelet, Dominique; Ciais, Philippe; Forrest, Matthew; Friedlingstein, Pierre; Hickler, Thomas; Kaplan, Jed O.; Kloster, Silvia; Knorr, Wolfgang; Lasslop, Gitta; Li, Fang; Mangeon, Stephane; Melton, Joe R.; Meyn, Andrea; Sitch, Stephen; Spessa, Allan; van der Werf, Guido R.; Voulgarakis, Apostolos; Yue, Chao

    2016-06-01

    Biomass burning impacts vegetation dynamics, biogeochemical cycling, atmospheric chemistry, and climate, with sometimes deleterious socio-economic impacts. Under future climate projections it is often expected that the risk of wildfires will increase. Our ability to predict the magnitude and geographic pattern of future fire impacts rests on our ability to model fire regimes, using either well-founded empirical relationships or process-based models with good predictive skill. While a large variety of models exist today, it is still unclear which type of model or degree of complexity is required to model fire adequately at regional to global scales. This is the central question underpinning the creation of the Fire Model Intercomparison Project (FireMIP), an international initiative to compare and evaluate existing global fire models against benchmark data sets for present-day and historical conditions. In this paper we review how fires have been represented in fire-enabled dynamic global vegetation models (DGVMs) and give an overview of the current state of the art in fire-regime modelling. We indicate which challenges still remain in global fire modelling and stress the need for a comprehensive model evaluation and outline what lessons may be learned from FireMIP.

  10. Impact of biomass burning on the atmosphere. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Dignon, J.

    1994-04-01

    Fire has played an important part in biogeochemical cycling throughout much of the history of our plant. This report addresses the coupled evolution of our planet`s atmospheric composition and biomass burning. Special attention is paid to the chemical and climatic impacts of biomass burning on the atmosphere throughout the last century, specifically looking at the cycles of carbon, nitrogen, and sulfur. Information from ice core measurements may be useful in understanding the history of fire and its historic affect on the composition of the atmosphere and climate.

  11. Adapting fire management to future fire regimes: impacts on boreal forest composition and carbon balance in Canadian National Parks

    Science.gov (United States)

    de Groot, W. J.; Flannigan, M. D.; Cantin, A.

    2009-04-01

    The effects of future fire regimes altered by climate change, and fire management in adaptation to climate change were studied in the boreal forest region of western Canada. Present (1975-90) and future (2080-2100) fire regimes were simulated for several National Parks using data from the Canadian (CGCM1) and Hadley (HadCM3) Global Climate Models (GCM) in separate simulation scenarios. The long-term effects of the different fire regimes on forests were simulated using a stand-level, boreal fire effects model (BORFIRE). Changes in forest composition and biomass storage due to future altered fire regimes were determined by comparing current and future simulation results. This was used to assess the ecological impact of altered fire regimes on boreal forests, and the future role of these forests as carbon sinks or sources. Additional future simulations were run using adapted fire management strategies, including increased fire suppression and the use of prescribed fire to meet fire cycle objectives. Future forest composition, carbon storage and emissions under current and adapted fire management strategies were also compared to determine the impact of various future fire management options. Both of the GCM's showed more severe burning conditions under future fire regimes. This includes fires with higher intensity, greater depth of burn, greater total fuel consumption and shorter fire cycles (or higher rates of annual area burned). The Canadian GCM indicated burning conditions more severe than the Hadley GCM. Shorter fire cycles of future fire regimes generally favoured aspen, birch, and jack pine because it provided more frequent regeneration opportunity for these pioneer species. Black spruce was only minimally influenced by future fire regimes, although white spruce declined sharply. Maintaining representation of pure and mixed white spruce ecosystems in natural areas will be a concern under future fire regimes. Active fire suppression is required in these areas. In

  12. Clean and efficient application of biomass for production of power and heat - Phase 3 in a long-term strategic research project

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.J.; Jensen, A.D.; Jensen, P.A.; Johnsson, J.E.; Dam-Johansen, K.

    2002-06-01

    This project contains activities on: Rheology of ashes from co-firing of coal and biomass; Investigation of ash and deposit formation in full-scale utility boilers; and Selective catalytic reduction: Deactivation under biomass combustion. A fly ash and deposit investigation was carried out as part of the SK Power Company test programme on co-firing of biomasses in a grate-fired boiler. The alternative biomasses (wood chips, olive stones and shea nuts) contain more K, S, and Cl, than wheat straw, and higher fly ash mass loading (mass of fly ash/volume of flue gas) was observed when co-firing alternative biomasses with wheat straw. Anyhow, no significant change in deposit structure when co-firing alkali-rich biomass was observed: KCl is glues residual ash particles together, independent of the feedstock mixture. Thus it can be concluded that co-firing of the actual biomasses in boilers designed for straw-firing, at the present shares is not problematic, from an ash formation and/or deposit build-up point-of-view. Anyhow the increase in ash mass loading in the flue gas, may cause increased build-up of particulate deposits in the convective pass of the boiler. Mature deposit samples from the Masnedoe and Ensted straw-fired boilers were investigated by SEM and EDX. Each deposit sample was classified into an inner, an intermediate, and an outer main layer. The outermost deposit layers at Masnedoe and Ensted looked chemically quite similar, even though they were of different colours. The intermediate layer at Ensted contained many Si- and Ca-rich particles glued together by melted KCI, while the intermediate deposit layers at Masnedoe were different. Since the straw fuels probably are similar, the differences observed in the deposit chemistry must be induced by the higher temperature of the Masnedoe deposit. An experimental method has been set up for viscosity determinations on ashes from co-firing with wheat straw. The method contains a pre-treatment of the ashes, where

  13. Clean and efficient application of biomass for production of power and heat - Phase 3 in a long-term strategic research project

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.J.; Jensen, A.D.; Jensen, P.A.; Johnsson, J.E.; Dam-Johansen, K.

    2002-06-01

    This project contains activities on: Rheology of ashes from co-firing of coal and biomass; Investigation of ash and deposit formation in full-scale utility boilers; and Selective catalytic reduction: Deactivation under biomass combustion. A fly ash and deposit investigation was carried out as part of the SK Power Company test programme on co-firing of biomasses in a grate-fired boiler. The alternative biomasses (wood chips, olive stones and shea nuts) contain more K, S, and Cl, than wheat straw, and higher fly ash mass loading (mass of fly ash/volume of flue gas) was observed when co-firing alternative biomasses with wheat straw. Anyhow, no significant change in deposit structure when co-firing alkali-rich biomass was observed: KCl is glues residual ash particles together, independent of the feedstock mixture. Thus it can be concluded that co-firing of the actual biomasses in boilers designed for straw-firing, at the present shares is not problematic, from an ash formation and/or deposit build-up point-of-view. Anyhow the increase in ash mass loading in the flue gas, may cause increased build-up of particulate deposits in the convective pass of the boiler. Mature deposit samples from the Masnedoe and Ensted straw-fired boilers were investigated by SEM and EDX. Each deposit sample was classified into an inner, an intermediate, and an outer main layer. The outermost deposit layers at Masnedoe and Ensted looked chemically quite similar, even though they were of different colours. The intermediate layer at Ensted contained many Si- and Ca-rich particles glued together by melted KCI, while the intermediate deposit layers at Masnedoe were different. Since the straw fuels probably are similar, the differences observed in the deposit chemistry must be induced by the higher temperature of the Masnedoe deposit. An experimental method has been set up for viscosity determinations on ashes from co-firing with wheat straw. The method contains a pre-treatment of the ashes, where

  14. Electrodialytic removal of Cd from biomass combustion fly ash suspensions

    OpenAIRE

    Kirkelund, Gunvor M.; Ottosen, Lisbeth M.; Damoe, Anne J.

    2013-01-01

    Due to relatively high concentrations of Cd, biomass combustion fly ashes often fail to meet Danish legislative requirements for recycling as fertilizer. In this study, the potential of using electrodialytic remediation for removal of Cd from four different biomass combustion fly ashes was investigated with the aim of enabling reuse of the ashes. The ashes originated from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. A series of laborat...

  15. Estimation of Direct Carbon Emissions from Chinese Forest Fires

    Institute of Scientific and Technical Information of China (English)

    TIANXiaorui; GAOChengde; SHULifu; WANGMingyu; YANGXiaohui

    2004-01-01

    Many studies indicated that the products of biosphere burning have short and long-term effects on the atmosphere. Vegetation burning can produce some gases which have significant influence on environment, including some greenhouse gases as CO2 and CH4, etc. Smoke aerosols produced from burning also influence global climate and atmospheric chemistry. The paper calculates the consumed biomass due to forest fires according to the statistics of forest fires from 1991 to 2000 and research results of biomass of Chinese forests. During the study period, forest fires burned average 5Tg-7Tg biomass each year and directly emitted 20.24 Tg-28.56 Tg carbon. In 1991-2000, average emission of carbon dioxide and CH4 account for 2.7%-3.9% and 3.3%-4.7% of the total emission of China (calculating with the data of 2000), respectively.

  16. Biomass Wet Firewood Experimental Study of the Direct-Fired Gasifier Performance%生物质湿柴直燃气化炉性能的试验研究

    Institute of Scientific and Technical Information of China (English)

    张巍; 王维新; 马飞

    2013-01-01

    为了研究生物质湿柴直燃气化炉在燃烧时秸秆的各个参数对其加热效率的影响规律,以热效率为评价指标,对棉花秸秆长度,棉花秸秆数量以及棉花秸秆含水率等试验因素进行中心组合试验,对结果进行了方差分析,研究各因素对湿柴炉加热效率影响的主次关系,确定较优参数组合.结果表明,棉花秸秆长度38.20 em、棉花秸秆数量67根、含水率15.40%时为较优参数组合.其热效率可达30.20%以上.%In order to graduate substance wet firewood direct-fired gasifier burning straw various parameters investigated its heating efficiency, thermal efficiency evaluation index, orthogonal experiment experimental factors of length of cotton stalks, cotton stalks, cotton stalks moistureand. Analysis of variance results, the study of various factors on the relationship between the primary and secondary the wet wood stove heating efficiency impact, determine the optimum parameters combination. The results show that: length 38.20cm, 15.40% of the cotton stalks the number of 67, the moisture content of cotton stalks as a combination of the optimum parameters, the thermal efficiency of up to 30.20%.

  17. A novel single-order diffraction grating: Random position rectangle grating

    Science.gov (United States)

    Zuhua, Yang; Qiangqiang, Zhang; Jing, Wang; Quanping, Fan; Yuwei, Liu; Lai, Wei; Leifeng, Cao

    2016-05-01

    Spectral diagnosis of radiation from laser plasma interaction and monochromation of radiation source are hot and important topics recently. Grating is one of the primary optical elements to do this job. Although easy to fabricate, traditional diffraction grating suffers from multi-order diffraction contamination. On the other hand, sinusoidal amplitude grating has the nonharmonic diffraction property, but it is too difficult to fabricate, especially for x-ray application. A novel nonharmonic diffraction grating named random position rectangle grating (RPRG) is proposed in this paper. Theoretical analysis and experiment results show that the RPRG is both higher order diffraction suppressing and not difficult to fabricate. Additionally, it is highly efficient; its first order absolute theoretical diffraction efficiency reaches 4.1%. Our result shows that RPRG is a novel tool for radiation diagnosis and monochromation. Project supported by the National Natural Science Foundation of China (Grant No. 11375160) and the National Science Instruments Major Project of China (Grant No. 2012YQ130125).

  18. Trends and future of fiber Bragg grating sensing technologies: tailored draw tower gratings (DTGs)

    Science.gov (United States)

    Lindner, E.; Hartung, A.; Hoh, D.; Chojetzki, C.; Schuster, K.; Bierlich, J.; Rothhardt, M.

    2014-05-01

    Today fiber Bragg gratings are commonly used in sensing technology as well as in telecommunications. Numerous requirements must be satisfied for their application as a sensor such as the number of sensors per system, the measurement resolution and repeatability, the sensor reusability as well as the sensor costs. In addition current challenges need to be met in the near future for sensing fibers to keep and extend their marketability such as the suitability for sterilization, hydrogen darkening or the separation of strain and temperature (or pressure and temperature). In this contribution we will give an outlook about trends and future of the fiber Bragg gratings in sensing technologies. Specifically, we will discuss how the use of draw tower grating technology enables the production of tailored Bragg grating sensing fibers, and we will present a method of separating strain and temperature by the use of a single Bragg grating only, avoiding the need for additional sensors to realize the commonly applied temperature compensation.

  19. High temperature corrosion in biomass incineration plants

    Energy Technology Data Exchange (ETDEWEB)

    Gotthjaelp, K.; Broendsted, P. [Risoe National Lab., Materials Dept. (Denmark); Jansen, P.; Markussen, J. [The Force Inst., Div. for Materials and Maintenance (Denmark); Montgomery, M.; Maahn, E. [DTU, Inst. of Manufacturing Engineering, Corrosion and Surface Technology (Denmark)

    1997-03-15

    The aim of the present project is to study the role of ash deposits in high temperature corrosion of superheater materials in biomass and refuse-fired combined heat and power plants. The project has included the two main activities: A chemical characterisation of ash deposits collected from a major number of biomass and refuse-fired combined heat and power plant boilers; Laboratory exposures and metallurgical examinations of material specimens with ash deposits in well-defined gas environments with HCl and SO{sub 2} in a furnace. In the first part of the project ash deposits were collected from the radiation chamber, superheater and economizer sections in both waste incineration and straw-fired/wood chip fired power plants. Thirteen plants participated in the investigations giving a total of 52 ash deposit samples. These were analysed using SEM-EDX. For refuse incineration, predominant elements are sodium, potassium, sulphur, chlorine, magnesium and calcium and in some cases zinc and lead. For straw or wood chip fired power plants, predominant elements are chlorine, sulphur,potassium and magnesium. The laboratory experiments were conducted using the electrically heated furnace rig for gaseous exposures. Two types of high temperature resistant steels, Sandvik 8LR30 (18Cr 10Ni Ti) and Sanicro 28 (27Cr 31Ni 4Mo) were investigated at 600 deg. C and 800 deg. C flue gas temperature and at a 600 deg. C metal temperature for up to 300 hours. Specimens which were embedded in ash deposits from a straw fired power plant were exposed to HCl (200 ppm) and SO{sub 2} (300 ppm). (EG)

  20. Fire Safety Technician

    Science.gov (United States)

    Moore, Pam

    2007-01-01

    Fire protection is one of the most important considerations in the construction and operation of industrial plants and commercial buildings. Fire insurance rates are determined by fire probability factors, such as the type of construction, ease of transporting personnel, and the quality and quantity of fire protection equipment available. Because…

  1. Chemical challenges to structural materials in oxyfuel-cofiring of coal and biomass

    Directory of Open Access Journals (Sweden)

    M.C. Mayoral

    2013-01-01

    Full Text Available Oxy-firing of solid fuels is one of the most relevant technological alternatives aiming at the CO2 capture in large-scale power plants. If oxy-firing is carried out in a fluidized bed reactor, the possibilities for application are extended to low-rank coals, difficult wastes, or biomass. The oxy-co-combustion of coal and biomass in circulating fluidized bed (CFB reactors would result in a negative balance for the CO2 emissions.

  2. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Greg F. Weber; Christopher J. Zygarlicke

    2001-05-01

    In summary, stoker-fired boilers that cofire or switch to biomass fuel may potentially have to deal with ash behavior issues such as production of different concentrations and quantities of fine particulate or aerosols and ash-fouling deposition. Stoker boiler operators that are considering switching to biomass and adding potential infrastructure to accommodate the switch may also at the same time be looking into upgrades that will allow for generating additional power for sale on the grid. This is the case for the feasibility study being done currently for a small (<1-MW) stoker facility at the North Dakota State Penitentiary, which is considering not only the incorporation of a lower-cost biomass fuel but also a refurbishing of the stoker boiler to burn slightly hotter with the ability to generate more power and sell excess energy on the grid. These types of fuel and boiler changes can greatly affect ash behavior issues.

  3. Hydrothermal pretreatment of biomass for pellet production

    Energy Technology Data Exchange (ETDEWEB)

    Tooyserkani, Z. [British Columbia Univ., Vancouver, BC (Canada). Clean Energy Research Centre, Biomass and Bioenergy Research Group

    2010-07-01

    This presentation discussed innovative technologies for the production of wood pellets using the hydrothermal pre-treatment of biomass. Conventional techniques use low-cost mill residues, such as saw dust and shavings, as feedstock to produce durable, low-ash pellets. However, mill residues are becoming less available as a result of fewer saw mills, increased pellet production, and increased competition for saw dust. Advanced techniques use mixed biomass such as logging residue as feedstock, creating pellets that are durable for handling and long-term storage, of a higher energy density for transport and mixing with coal for co-firing, and a choice feedstock for biofuels. Advanced pellet production uses steam explosion/pre-treatment in which biomass receives a short-term high-pressure steam treatment followed by sudden decompression. Mild torrefaction seems to have positive feedback, and steam-treated pellets are durable with superior hydrophobicity. 3 figs., 3 tabs.

  4. Fundamentals of Fire Phenomena

    DEFF Research Database (Denmark)

    Quintiere, James

    Understanding fire dynamics and combustion is essential in fire safety engineering and in fire science curricula. Engineers and students involved in fire protection, safety and investigation need to know and predict how fire behaves to be able to implement adequate safety measures and hazard...... analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...... discipline. It covers thermo chemistry including mixtures and chemical reactions; Introduces combustion to the fire protection student; Discusses premixed flames and spontaneous ignition; Presents conservation laws for control volumes, including the effects of fire; Describes the theoretical bases...

  5. External benefits of biomass-e in Spain: an economic valuation.

    Science.gov (United States)

    Soliño, Mario

    2010-03-01

    This article analyses the willingness to pay for a program that promotes the production of electricity from forest biomass, instead of that based on fossil fuels. The program decreases greenhouse gas emissions, reduces the pressure on non-renewable resources, lowers the risk of summer forest fires, creates employment in rural areas. Results from a choice experiment show that consumers are willing to pay a higher price for electricity in order to obtain the external benefits of the substitution. Respondents attach a higher value to programs that decrease the pressure of non-renewable resources and the risk of forest fires.

  6. Development and testing of a dedusting filter system for exhaust gases of domestic small firing systems for the combustion of biomass and waste materials; Entwicklung und Erprobung eines Abreinigungsfilters fuer das Abgas haeuslicher Kleinfeuerungsanlagen fuer die Verbrennung von Biomasse und Abfaellen

    Energy Technology Data Exchange (ETDEWEB)

    Aleysa, Mohammadshayesh

    2012-07-01

    The author describes the development of a dedusting filter system which should be suitable for the dedusting of exhaust gases in domestic small firing installations with a power output of 40 kW. This filter system should undoubtedly enable the necessary capture efficiency. It should be implemented with little technical complexity as well as low maintenance and cost-effectivity. The dedusting filter system is tested in connection with a wood gasification boiler as well as a pellet incinerator. The quantities and parameters of smoke gas, the pressure losses, the precipitation capacity, the economic efficiency and the practical suitability of the dedusting filter system are investigated. Furthermore, the author determines the necessary factors for the design and dimensioning of dedusting filter systems.

  7. Fire-Walking

    Science.gov (United States)

    Willey, David

    2010-01-01

    This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

  8. FIRE EXTINGUISHER TRAINING

    OpenAIRE

    Jyoti Sanjay Yadav

    2013-01-01

    Afire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i.e., no escape route, smoke, explosion hazard, etc.), or otherwise requires the expertise of a fire department. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel contain...

  9. Fire-induced Carbon Emissions and Regrowth Uptake in Western U.S. Forests: Documenting Variation Across Forest Types, Fire Severity, and Climate Regions

    Science.gov (United States)

    Ghimire, Bardan; Williams, Christopher A.; Collatz, George James; Vanderhoof, Melanie

    2012-01-01

    The forest area in the western United States that burns annually is increasing with warmer temperatures, more frequent droughts, and higher fuel densities. Studies that examine fire effects for regional carbon balances have tended to either focus on individual fires as examples or adopt generalizations without considering how forest type, fire severity, and regional climate influence carbon legacies. This study provides a more detailed characterization of fire effects and quantifies the full carbon impacts in relation to direct emissions, slow release of fire-killed biomass, and net carbon uptake from forest regrowth. We find important variations in fire-induced mortality and combustion across carbon pools (leaf, live wood, dead wood, litter, and duff) and across low- to high-severity classes. This corresponds to fire-induced direct emissions from 1984 to 2008 averaging 4 TgC/yr and biomass killed averaging 10.5 TgC/yr, with average burn area of 2723 sq km/yr across the western United States. These direct emission and biomass killed rates were 1.4 and 3.7 times higher, respectively, for high-severity fires than those for low-severity fires. The results show that forest regrowth varies greatly by forest type and with severity and that these factors impose a sustained carbon uptake legacy. The western U.S. fires between 1984 and 2008 imposed a net source of 12.3 TgC/yr in 2008, accounting for both direct fire emissions (9.5 TgC/yr) and heterotrophic decomposition of fire-killed biomass (6.1 TgC yr1) as well as contemporary regrowth sinks (3.3 TgC/yr). A sizeable trend exists toward increasing emissions as a larger area burns annually.

  10. Grate monitoring systems, state of the art; Metoder foer rosteroevervakning, dagslaegesbestaemning

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet [Aaf Processdesign AB, Linkoeping (Sweden)

    2001-01-01

    During a number of years research and development projects have been made to present methods of monitoring the grate in a grate fired boiler. The monitoring is interesting in order to be able to increase efficiency, increase burn-out of ash, improve the status of emissions, improve transportation of ash and fuel through the furnace, reduce costs for operation and maintenance, handle greater loads etc. Improvement of the combustion has been concentrated to the development of the gas phase combustion. In the past few years the computer development has progressed rapidly and the use of optical monitoring methods have been made possible for monitoring grates. To analyse state of the art of optical grate monitoring systems three different methods have been used, literature search, inquiry where plant owners were asked if they have used grate monitoring systems and if so what experiences they have, and interviews with scientists and users. The inquiry investigation was made during spring 2000 and supplemented with a few known users of grate monitoring systems in august 2000. The interviews were made during august 2000. The methods which have been examined are: Video monitoring; Computer vision; IR-pyrometry; IR-camera technology; Laser measuring methods; Acoustic pyrometry. The survey showed that video monitoring is useful to monitor the fuel bed and an aid to the operators. A good cooling and cleansing system is essential to make the system reliable. If the system is aided with computer vision the computer will show numbers which can be used in the control system. These have been tried at a couple of sites but the system is still being developed and no sites uses this function fully automated. Infrared measurements have been tried in number of research projects. The IR-pyrometer technique is good for measuring temperature but the reliability is too low for some of the users. IR-cameras are used in several waste incineration plants to control the combustion. The systems

  11. Holocene fire history reconstruction using Tibetan lacustrine sediments

    Science.gov (United States)

    Callegaro, Alice; Kirchgeorg, Torben; Battistel, Dario; Bird, Broxton; Barbante, Carlo

    2016-04-01

    The important role that biomass burning playsin influencing the Holocene'sclimate is still under discussion. The present work gives information about past biomass burning events in the Tibetan Plateau and helps to increase the understanding of the interaction between climate, humans and fire activity during Holocene. Asiatic area is one of the centers of the advent of agriculture and pastoralism, and it is a strategic area for understanding the interaction between human and fire during the Holocene. We reconstructed past biomass burning events and vegetation from sediments collected from lake Paru Co, a small moraine dammed lake located in the Tibetan Plateau at 4845 m above sea level. We extracted lake sediment samples by accelerate solvent extraction and analysed different organic molecular proxies by GC-MS and IC-MS. We used monosaccharide anhydrides, levoglucosan and its isomers, as proxies for biomass burning. These are specific molecular markers originated from the pyrolysis of cellulose showing significant fire events and indicate changes in burned fuel. Furthermore we analysed polycyclic aromatic hydrocarbons (PAH) as additional combustion proxies. For a better understanding of changes in vegetation andof human habitation at the lake shore we analysed n-alkanes and sterols. Comparing the data of this multi-proxy approach used in the studied area with climatic and meteorological literature data, reconstruction and contextualization of past fire events are possible: we can see the agreement between dry climate period and presence of more intense fire events, especially in the Early Holocene.

  12. Characterization and quantification of deposits build up and removal in straw suspension fired boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt; Shafique Bashir, Muhammad; Wedel, Stig;

    This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed...... by conducting advanced probe measurements at the Amagerværkets Vattenfall owed boilers. It was the objective of the project to provide an improved understanding of ash deposit formation and removal in biomass suspension fired boilers. The project have provided a large amount of knowledge on the following issues......: 1) The influence of local boiler conditions on deposit formation in suspension fired boilers using wood or co-firing straw and wood, 2) quantification of deposit removal in biomass suspension firing boilers with regards both to natural shedding and soot blower induced shedding, 3) established...

  13. Carbon emissions associated with forest fires in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Alencar, A.; Nepstad, D.; Moutinho, P. [Instituto de Pesquisa Ambiental da Amazonia, Belem, Para (Brazil)

    2005-07-01

    Forest fires or 'understory fires' that burn beneath forest canopies are one of the most important types of forest impoverishment in the Amazon causing large emissions of carbon to the atmosphere. The occurrence and the damage intensity of these fire events are related to the synergetic influence of selective logging, forest fragmentation and severe droughts especially such as that associated with El Nino Southern Oscillation (ENSO) episodes. In addition, forest fires occurrence also depends on landscape variables and forest structure. In this chapter we review the feedbacks that increase the susceptibility of the forest to understory fires, evaluate the impact of the fire events on forest biomass, analyze the spatial relationship of these forest fires with landscape characteristics for different regions along the arc of deforestation and estimate the area affected by forest fires in El Nino and non El Nino years. The results indicate that the area of forest burned by understory forest fire during the severe drought (ENSO) year (approximately 43.9 millions of hectares) was 13 times greater than the area burned during the average rainfall year (0.2 million hectares), and twice the area of annual deforestation. Our estimate of aboveground forest carbon that will eventually be released to the atmosphere through decomposition of dead trees due to understory fires in the Amazon arc of deforestation ranged from 0.024 to 0.165 Pg during the ENSO and from 0.001 to 0.011 Pg during the non ENSO years.

  14. Experimental facility for analysis of biomass combustion characteristics

    Directory of Open Access Journals (Sweden)

    Miljković Biljana M.

    2015-01-01

    Full Text Available The objective of the present article is to present an experimental facility which was designed and built at the Faculty of Technical Sciences in order to study the combustion of different sorts of biomass and municipal solid waste. Despite its apparent simplicity, direct combustion is a complex process from a technological point of view. Conventional combustion equipment is not designed for burning agricultural residues. Devices for agricultural waste combustion are still in the development phase, which means that adequate design solution is presently not available at the world market. In order to construct a boiler and achieve optimal combustion conditions, it is necessary to develop a mathematical model for biomass combustion. Experimental facility can be used for the collection of data necessary for detailed modelling of real grate combustor of solid biomass fuels. Due to the complexity of the grate combustion process, its mathematical models and simulation software tools must be developed and verified using experimental data. This work highlights the properties required for the laboratory facility designed for the examination of biomass combustion and discusses design and operational issues.

  15. Influence of Biomass Burning Aerosols on Southeast Asia Air Quality

    Science.gov (United States)

    Lee, Hsiang-He; Bar-Or, Rotem; Wang, Chien

    2016-04-01

    Biomass burning activities in Southeast Asia have become a major concern of general public as well as governments in the region. This is because that aerosols emitted from such fires can cause long-lasting haze events under favorite weather conditions in downwind locations such as Singapore, degrading air quality and causing human health issues. In order to improve our understanding of the spatiotemporal coverage and influence of biomass burning aerosols in Southeast Asia, we have used the Weather Research and Forecasting (WRF) model with a smoke aerosol module to conduct multi-year simulations covering the period from 2002 to 2014, driven by the biomass burning emissions from the Fire INventory from NCAR (FINN) version 1.5. To attribute the aerosol influences over various target regions to specific fire locations, we have also partitioned aerosols emitted from five major fire regions of Southeast Asia in the simulations. Based on the simulation results, we have examined the influences of various meteorological regimes on the aerosol transport and wet removal. We find that the transport and scavenging of biomass burning aerosols are strongly modulated by the Southeast Asian monsoon wind field and precipitation. We also identified that in the past decade, smoke aerosols are responsible for a substantial fraction of low visibility events in the major metropolitan areas of the region: 35% in Bangkok, 25% in Kuala Lumpur, 16% in Singapore, and 22% in Jakarta. The fires in the Indochina peninsula account for the largest percentage of the total fire enhancement to PM2.5 in Bangkok (98.9%), and fires in Sumatra were the major contributor in Kuala Lumpur (49%), Singapore (39%), and Jakarta (48%).

  16. Environmental assessment of gasification technology for biomass conversion to energy in comparison with other alternatives

    DEFF Research Database (Denmark)

    Nguyen, T Lan T; Hermansen, John Erik; Nielsen, Rasmus Glar

    2013-01-01

    This paper assesses the environmental performance of biomass gasification for electricity production based on wheat straw and compares it with that of alternatives such as straw-fired electricity production and fossil fuel-fired electricity production. In the baseline simulation, we assume that t...

  17. Production of peroxy nitrates in boreal biomass burning plumes over Canada during the BORTAS campaign

    Directory of Open Access Journals (Sweden)

    M. Busilacchio

    2016-03-01

    during biomass burning is significant in the O3 budget. The implication of these observations is that fire emissions in some cases, for example boreal forest fires and in the conditions reported here, may influence more long-lived precursors of O3 than short-lived pollutants, which in turn can be transported and eventually diluted in a wide area.

  18. Torrefaction of herbaceous biomass: A study of product, process and technology

    NARCIS (Netherlands)

    Joshi, Y.V.

    2015-01-01

    Co-firing biomass with coal in pulverized fuel boilers is a readily implementable means for attaining renewable electricity generation targets. Even as utilities have gained considerable operational experience over the past years with co-firing small quantities (0-3% on energy basis) of assorted bio

  19. Self-referenced waveguide grating sensor.

    Science.gov (United States)

    Kehl, Florian; Follonier, Stephane

    2016-04-01

    Like any other sensor system, performances of waveguide grating couplers are affected by adverse effects such as noise and drift, mainly limiting the devices' resolution and long-term stability. It is therefore often required to reference the measurement with a secondary, parallel sensor to decrease these undesired influences. Here we present a simple but effective method to self-reference a label-free waveguide grating coupler by partially coating and thereby passivating the sensitive area with an inert layer. The presented waveguide grating chip design offers the advantage of internal self-referencing for adverse effects, such as inherent system instabilities, mechanical disturbance, or temperature drift, without the need of a sacrificial reference channel. PMID:27192258

  20. Ultra-high density diffraction grating

    Science.gov (United States)

    Padmore, Howard A.; Voronov, Dmytro L.; Cambie, Rossana; Yashchuk, Valeriy V.; Gullikson, Eric M.

    2012-12-11

    A diffraction grating structure having ultra-high density of grooves comprises an echellette substrate having periodically repeating recessed features, and a multi-layer stack of materials disposed on the echellette substrate. The surface of the diffraction grating is planarized, such that layers of the multi-layer stack form a plurality of lines disposed on the planarized surface of the structure in a periodical fashion, wherein lines having a first property alternate with lines having a dissimilar property on the surface of the substrate. For example, in one embodiment, lines comprising high-Z and low-Z materials alternate on the planarized surface providing a structure that is suitable as a diffraction grating for EUV and soft X-rays. In some embodiments, line density of between about 10,000 lines/mm to about 100,000 lines/mm is provided.

  1. Efficient EUV transmission gratings for plasma diagnostics

    Science.gov (United States)

    Braig, Christoph; Kley, Ernst-Bernhard

    2010-07-01

    We report on a theoretical study of binary phase transmission gratings for high-resolution EUV and soft X-ray spectroscopy and investigate their optical properties. Designed for wavelengths between about 2 and 40 nm, the devices may provide a first order diffraction efficiency beyond 30%. We use RCWA methods in order to optimize the grating design parameters and discuss special features of segmented grating arrays. Several elemental as well as compound materials like Be, Mo, LiF and PMMA are considered with respect to their potential and practical limitations in terms of feasibility and sensitivity to radiation damage. Simulations are performed for several samples on the radiation produced by a table-top EUV plasma source and applications to astrophysical problems are considered.

  2. Plasmonic Transmission Gratings – Fabrication and Characterization

    DEFF Research Database (Denmark)

    Sierant, Aleksandra; Jany, Benedykt; Bartoszek-Bober, Dobrosława;

    realization is given by the use of a metallic diffraction grating, where the diffracted light couples to the SPP. Here, we propose metallic periodic transmission gratings, processed onto a glass substrate, with various periods and fill factors. The gratings are milled in a plain gold layer with a focused ion......Surface plasmon polaritons (SPPs) are collective electron oscillations, confined at metal-dielectric interfaces. Coupling incident photons to SPPs may lead to spectrally broad field enhancement and confinement below the diffraction limit [1]. This phenomenon facilitates various applications......) Simulations. [1] W. L. Barnes, A. Dereux, T. W. Ebbesen, Nature 424, 824–830 (2003) [2] X. D. Hoa, A. G. Kirk, M. Tabrizian, Biosensors and Bioelectronics, 23, 2, 151-160 (2007) [3] T. Kawalec, et al., Opt. Lett. 39, 2932 (2014)...

  3. Ultrabroadband TM reflection from high contrast grating: why?

    NARCIS (Netherlands)

    Gushchin, I.; Tishchenko, A.V.; Parriaux, O.; Hoekstra, H.J.W.M.

    2009-01-01

    A grating mode analysis of the unusually broadband TM reflection from a high contrast binary grating sheds light on the origin of this effect. This interpretation will be submitted to the workshop attendance.

  4. Theoretical analysis on x-ray cylindrical grating interferometer

    CERN Document Server

    Cong, Wenxiang; Wang, Ge

    2015-01-01

    Grating interferometer is a state of art x-ray imaging approach, which can simultaneously acquire information of x-ray attenuation, phase shift, and small angle scattering. This approach is very sensitive to micro-structural variation and offers superior contrast resolution for biological soft tissues. The present grating interferometer often uses flat gratings, with serious limitations in the field of view and the flux of photons. The use of curved gratings allows perpendicular incidence of x-rays on the gratings, and gives higher visibility over a larger field of view than a conventional interferometer with flat gratings. In the study, we present a rigorous theoretical analysis of the self-imaging of curved transmission gratings based on Rayleigh-Sommerfeld diffraction. Numerical simulations have demonstrated the self-imaging phenomenon of cylindrical grating interferometer. The theoretical results are in agreement with the results of numerical simulations.

  5. Multiwavelength optical scatterometry of dielectric gratings

    KAUST Repository

    Yashina, Nataliya P.

    2012-08-01

    Modern scatterometry problems arising in the lithography production of periodic gratings are in the focus of the work. The performance capabilities of a novel theoretical and numerical modeling oriented to these problems are considered. The approach is based on rigorous solutions of 2-D initial boundary value problems of the gratings theory. The quintessence and advantage of the method is the possibility to perform an efficient analysis simultaneously and interactively both for steady state and transient processes of the resonant scattering of electromagnetic waves by the infinite and compact periodic structures. © 2012 IEEE.

  6. Novel algorithm for synthesis of fiber gratings

    Institute of Scientific and Technical Information of China (English)

    Bo LV; Ming CHEN; Dan LU; Taorong GONG; Tangjun LI; Shuisheng JIAN

    2009-01-01

    A novel algorithm for the synthesis of fiber gratings is presented.For the first time we propose an effective optimal approach to construct a coupling coefficient function by employing 4th-order Runge-Kutta (R-K) analysis method for calculating the reflection spectra of fiber gratings.The numerical results show that with this proposed method, some required optical filters have been yielded with better features compared with other methods such as Gel'Fand-Levitan-Marchenko (GLM) algorithm.In addition, the performance of different interpolation functions particularly utilized in our algorithm, including linear-type, spline-type, and Hermit-type, are discussed in detail.

  7. Characteristics of Smart Concrete with Fiber Optical Bragg Grating Sensor

    Institute of Scientific and Technical Information of China (English)

    XIN Si-jin; JIANG De-sheng; LIANG Lei; Luo Pei; ZUO Jun; NAN Qiu-ming; CHEN Da-xiong

    2004-01-01

    Based on the advantages of the fiber Bragg grating sensing technology, this paper presents a principle of a novel smart concrete with fiber optical Bragg grating sensor, analyses the theory and characteristics,illustrates the key technology and method to make the fiber Bragg grating sensor for the smart concrete, and proves the feasibility with experiments. The results indicate that the smart concrete with fiber Bragg grating sensors is feasible in the structure monitoring and damage diagnosing in the long run.

  8. Application of spherical gratings in synchrotron radiation spectroscopy

    International Nuclear Information System (INIS)

    The recent development in gracing incidence grating monochromator design is discussed and the performance limiting for such instruments are examined. Especially the aberrations of toroidal and spherical gratings are investigated using the optical path function concept. It is shown that large radius spherical gratings, which can be produced with better slope tolerances than aspherics, also yield smaller overall line curvature than toroids. Therefore, a new simple spherical grating monochromator design is proposed and its performance is analyzed

  9. Theoretical analysis on x-ray cylindrical grating interferometer

    OpenAIRE

    Cong, Wenxiang; Xi, Yan; Wang, Ge

    2015-01-01

    Grating interferometer is a state of art x-ray imaging approach, which can simultaneously acquire information of x-ray attenuation, phase shift, and small angle scattering. This approach is very sensitive to micro-structural variation and offers superior contrast resolution for biological soft tissues. The present grating interferometer often uses flat gratings, with serious limitations in the field of view and the flux of photons. The use of curved gratings allows perpendicular incidence of ...

  10. Pretreated densified biomass products

    Science.gov (United States)

    Dale, Bruce E; Ritchie, Bryan; Marshall, Derek

    2014-03-18

    A product comprising at least one densified biomass particulate of a given mass having no added binder and comprised of a plurality of lignin-coated plant biomass fibers is provided, wherein the at least one densified biomass particulate has an intrinsic density substantially equivalent to a binder-containing densified biomass particulate of the same given mass and h a substantially smooth, non-flakey outer surface. Methods for using and making the product are also described.

  11. Energy use of biomass

    OpenAIRE

    HOLEČKOVÁ, Michaela

    2010-01-01

    The aim of this bachelor thesis is the research of different types of biomass, description of the various types of methods and technologies for energy usage of biomass and the mapping of large power plant units in the Czech Republic. The first part of this thesis deals with the definition of biomass, its distribution and the description of basic essential attributes describing its composition. The downstream part of this work is focused on the technologies of gaining energy out of biomass or ...

  12. Laser Trimming for Adjustment of Grating Offset in Phase-Shifted Fiber Grating Coupler for All-Optical Switching Application

    Institute of Scientific and Technical Information of China (English)

    Hirohisa; Yokota; Yutaka; Sasaki

    2003-01-01

    We theoretically investigated laser trimming to adjust grating offset in phase-shifted fiber grating coupler (FGC) for all-optical switching application. It was clarified that the trimming made the extinction ratio higher in all-optical FGC switch.

  13. Fabrication of Dammann Gratings Inside Glasses by a Femtosecond Laser

    Institute of Scientific and Technical Information of China (English)

    NAKAYA Takayuki; QIU Jian-Rong; ZHOU Chang-He; HIRAO Kazuyuki

    2004-01-01

    @@ Dammann grating is useful in information technology as an optical splitter. It is usually fabricated through complicated processes. Here we report on the direct fabrication of a 6 × 6 Dammann grating in a silica glass by an 800nm femtosecond laser. We also discuss the relationship between diffraction efficiency of 1 × 2 Dammann grating and laser irradiation conditions.

  14. Slow light via a tapered grating: transfer matrix approach

    NARCIS (Netherlands)

    Valkering, Theo P.

    2006-01-01

    Reflection properties of a nonuniform apodized Bragg grating connecting a homogeneous medium with a (half-infinite) uniform grating are investigated for system parameters such that the group velocity in the uniform grating is low. In particular a smooth polynomial transition of the index profile to

  15. Liquid filling of photonic crystal fibres for grating writing

    DEFF Research Database (Denmark)

    Sørensen, Henrik Rokkjær; Canning, John; Lægsgaard, Jesper;

    2007-01-01

    liquid filling of photonic crystal fibres reduces the scattering from air–glass interfaces during Bragg grating writing in many layered photonic crystal fibres. Within experimental uncertainty, the grating index modulation of a grating written in germanium-doped photonic crystal fibre with 10 rings...

  16. Off-plane x-ray reflection grating fabrication

    Science.gov (United States)

    Peterson, Thomas J.; DeRoo, Casey T.; Marlowe, Hannah; McEntaffer, Randall L.; Miles, Drew M.; Tutt, James H.; Schultz, Ted B.

    2015-09-01

    Off-plane X-ray diffraction gratings with precision groove profiles at the submicron scale will be used in next generation X-ray spectrometers. Such gratings will be used on a current NASA suborbital rocket mission, the Off-plane Grating Rocket Experiment (OGRE), and have application for future grating missions. The fabrication of these gratings does not come without challenges. High performance off-plane gratings must be fabricated with precise radial grating patterns, optically at surfaces, and specific facet angles. Such gratings can be made using a series of common micro-fabrication techniques. The resulting process is highly customizable, making it useful for a variety of different mission architectures. In this paper, we detail the fabrication method used to produce high performance off-plane gratings and report the results of a preliminary qualification test of a grating fabricated in this manner. The grating was tested in the off-plane `Littrow' configuration, for which the grating is most efficient for a given diffraction order, and found to achieve 42% relative efficiency in the blaze order with respect to all diffracted light.

  17. Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

    Science.gov (United States)

    Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

    2016-03-01

    The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia. PMID:26503008

  18. Proteins in biomass streams

    NARCIS (Netherlands)

    Mulder, W.J.

    2010-01-01

    The focus of this study is to give an overview of traditional and new biomasses and biomass streams that contain proteins. When information was available, the differences in molecular structure and physical and chemical properties for the different proteins is given. For optimal biomass use, isolati

  19. Evaluation of two emergency treatments for reducing post-fire runoff and sediment losses

    Directory of Open Access Journals (Sweden)

    A. Lombao

    2013-01-01

    Full Text Available A field experiment was conducted in a burnt area affected by a high severity fire located in Laza (Ourense to evaluate the impact of fire and different post-fire stabilisation treatments like mulching and seeding on microbial biomass. Samples were collected from the A horizon (0-2 cm immediately and 4, 8 and 12 months after the wildfire. Total biomass and biomass of specific groups (bacteria, fungi, actinomycetes, Gram-positive bacteria and Gram-negative bacteria were determined in the fraction < 2mm by analysis of phospholipid fatty acids. Results showed that total biomass and biomass of specific groups decreased immediately after the wildfire and although this effect is was attenuated over time it still persisted after 1 year. Fungal/bacterial and G -/G+ ratios as well as actinomycetes abundance increased in burnt soil samples due to changes in soil pH and carbon content. The ratio of cyclopropyl fatty acid/monoeic precursors (cyclo/prec tended to be higher in the burned soils than in the unburned control, indicating that the fire caused stress in soil microorganisms. There was no evidence of any significant difference on total biomass, biomass of specifics groups and microbial fatty acids indices (fungal/bacterial, G-/G+, cyclo/pre between the two different post-fire treatments (QS, QM and the corresponding burned treatment (Q.

  20. Experimental Investigation on NOx Reduction by Primary Measures in Biomass Combustion: Straw, Peat, Sewage Sludge, Forest Residues and Wood Pellets

    Directory of Open Access Journals (Sweden)

    Øyvind Skreiberg

    2012-02-01

    Full Text Available An experimental investigation was carried out to study the NOx formation and reduction by primary measures for five types of biomass (straw, peat, sewage sludge, forest residues/Grot, and wood pellets and their mixtures. To minimize the NOx level in biomass-fired boilers, combustion experiments were performed in a laboratory scale multifuel fixed grate reactor using staged air combustion. Flue gas was extracted to measure final levels of CO, CO2, CxHy, O2, NO, NO2, N2O, and other species. The fuel gas compositions between the first and second stage were also monitored. The experiments showed good combustion quality with very low concentrations of unburnt species in the flue gas. Under optimum conditions, a NOx reduction of 50–80% was achieved, where the highest reduction represents the case with the highest fuel-N content. The NOx emission levels were very sensitive to the primary excess air ratio and an optimum value for primary excess air ratio was seen at about 0.9. Conversion of fuel nitrogen to NOx showed great dependency on the initial fuel-N content, where the blend with the highest nitrogen content had lowest conversion rate. Between 1–25% of the fuel-N content is converted to NOx depending on the fuel blend and excess air ratio. Sewage sludge is suggested as a favorable fuel to be blended with straw. It resulted in a higher NOx reduction and low fuel-N conversion to NOx. Tops and branches did not show desirable NOx reduction and made the combustion also more unstable. N2O emissions were very low, typically below 5 ppm at 11% O2 in the dry flue gas, except for mixtures with high nitrogen content, where values up to 20 ppm were observed. The presented results are part of a larger study on problematic fuels, also considering ash content and corrosive compounds which have been discussed elsewhere.

  1. Water vapor release from biomass combustion

    Directory of Open Access Journals (Sweden)

    R. S. Parmar

    2008-10-01

    Full Text Available We report on the emission of water vapor from biomass combustion. Concurrent measurements of carbon monoxide and carbon dioxide are used to scale the concentrations of water vapor found, and are referenced to carbon in the biomass. The investigated fuel types include hardwood (oak and African musasa, softwood (pine and spruce, partly with green needles, and African savanna grass. The session-averaged ratio of H2O to the sum of CO and CO2 in the emissions from 16 combustion experiments ranged from 1.2 to 3.7, indicating the presence of water that is not chemically bound. This non-bound biomass moisture content ranged from 33% in the dry African hardwood, musasa, to 220% in fresh pine branches with needles. The moisture content from fresh biomass contributes significantly to the water vapor in biomass burning emissions, and its influence on the behavior of fire plumes and pyro-cumulus clouds needs to be evaluated.

  2. Investigation of Heat Generation from Biomass Fuels

    Directory of Open Access Journals (Sweden)

    Naoharu Murasawa

    2015-06-01

    Full Text Available New biomass fuels are constantly being developed from renewable resources in an effort to counter global warming and to create a sustainable society based on recycling. Among these, biomass fuels manufactured from waste are prone to microbial fermentation, and are likely to cause fires and explosions if safety measures, including sufficient risk assessments and long-term storage, are not considered. In this study, we conducted a series of experiments on several types of newly developed biomass fuels, using combinations of various thermal- and gas-analysers, to identify the risks related to heat- and gas-generation. Since a method for the evaluation of the relative risks of biomass fuels is not yet established in Japan, we also such a method based on our experimental results. The present study found that in cases where safety measures are not thoroughly observed, biomass fuels manufactured from waste materials have a higher possibility of combusting spontaneously at the storage site due to microbial fermentation and heat generation.

  3. COFIRING BIOMASS WITH LIGNITE COAL; FINAL

    International Nuclear Information System (INIS)

    The University of North Dakota Energy and Environmental Research Center, in support of the U.S. Department of Energy's (DOE) biomass cofiring program, completed a Phase 1 feasibility study investigating aspects of cofiring lignite coal with biomass relative to utility-scale systems, specifically focusing on a small stoker system located at the North Dakota State Penitentiary (NDSP) in Bismarck, North Dakota. A complete biomass resource assessment was completed, the stoker was redesigned to accept biomass, fuel characterization and fireside modeling tests were performed, and an engineering economic analysis was completed. In general, municipal wood residue was found to be the most viable fuel choice, and the modeling showed that fireside problems would be minimal. Experimental ash deposits from firing 50% biomass were found to be weaker and more friable compared to baseline lignite coal. Experimental sulfur and NO(sub x) emissions were reduced by up to 46%. The direct costs savings to NDSP, from cogeneration and fuel saving, results in a 15- to 20-year payback on a$1,680,000 investment, while the total benefits to the greater community would include reduced landfill burden, alleviation of fees for disposal by local businesses, and additional jobs created both for the stoker system as well as from the savings spread throughout the community

  4. Holographic reflection gratings in photopolymerizable solgel materials

    Science.gov (United States)

    Murciano, A.; Blaya, S.; Carretero, L.; Madrigal, R. F.; Fimia, A.

    2006-08-01

    The recording of holographic reflection gratings with a spatial frequency higher than 5400 lines/mm in photopolymerizable solgel materials is experimentally demonstrated. Diffraction efficiencies near 60% and a FWHM of 2.5 nm centered at 531.5 nm are achieved. Moreover, the effect of the energetic exposure is characterized at different recording intensities.

  5. Speed enhancement in VCSELs employing grating mirrors

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2013-01-01

    In recent years, various approaches to improve the speed of directly modulated vertical-cavity surface-emitting lasers (VCSELs) have been reported and demonstrated good improvement. In this paper, we propose and numerically investigate a new possibility of using high-index-contrast grating (HCG...

  6. Undergraduate Experiment with Fractal Diffraction Gratings

    Science.gov (United States)

    Monsoriu, Juan A.; Furlan, Walter D.; Pons, Amparo; Barreiro, Juan C.; Gimenez, Marcos H.

    2011-01-01

    We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics…

  7. Detailed Investigations of Load Coefficients on Grates

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Rasmussen, Michael R.; Frigaard, Peter

    In this report is presented the results of model tests carried out at Dept. of Civil Engineering, aalborg University (AAU) on behalf of DONG Energy A/S and Vattenfall A/S, Denmark. The objective of the tests was to investigate the load coefficient on different grates and a solid plate for designing...

  8. Smart photogalvanic running-grating interferometer

    DEFF Research Database (Denmark)

    Kukhtarev, N. V.; Kukhtareva, T.; Edwards, M. E.;

    2005-01-01

    Photogalvanic effect produces actuation of periodic motion of macroscopic LiNbO3 crystal. This effect was applied to the development of an all-optical moving-grating interferometer usable for optical trapping and transport of algae chlorella microorganisms diluted in water with a concentration...

  9. Fiber Bragg Grating Filter High Temperature Sensors

    Science.gov (United States)

    Lyons, Donald R.; Brass, Eric D.; Pencil, Eric (Technical Monitor)

    2001-01-01

    We present a scaled-down method for determining high temperatures using fiber-based Bragg gratings. Bragg gratings are distributed along the length of the optical fiber, and have high reflectivities whenever the optical wavelength is twice the grating spacing. These spatially distinct Bragg regions (located in the core of a fiber) are sensitive to local temperature changes. Since these fibers are silica-based they are easily affected by localized changes in temperature, which results in changes to both the grating spacing and the wavelength reflectivity. We exploit the shift in wavelength reflectivity to measure the change in the local temperature. Note that the Bragg region (sensing area) is some distance away from where the temperature is being measured. This is done so that we can measure temperatures that are much higher than the damage threshold of the fiber. We do this by affixing the fiber with the Bragg sensor to a material with a well-known coefficient of thermal expansion, and model the heat gradient from the region of interest to the actual sensor. The research described in this paper will culminate in a working device as well as be the second portion of a publication pending submission to Optics Letters.

  10. Computer simulation of multiple dynamic photorefractive gratings

    DEFF Research Database (Denmark)

    Buchhave, Preben

    1998-01-01

    The benefits of a direct visualization of space-charge grating buildup are described. The visualization is carried out by a simple repetitive computer program, which simulates the basic processes in the band-transport model and displays the result graphically or in the form of numerical data. The...

  11. High-index-contrast subwavelength grating VCSEL

    DEFF Research Database (Denmark)

    Gilet, Philippe; Olivier, Nicolas; Grosse, Philippe;

    2010-01-01

    In this article, we report our results on 980nm high-index-contrast subwavelength grating (HCG) VCSELs for optical interconnection applications. In our structure, a thin undoped HCG layer replaces a thick p-type Bragg mirror. The HCG mirror can feasibly achieve polarization-selective reflectivities...

  12. Diffraction from fractal grating Cantor sets

    Science.gov (United States)

    Golmankhaneh, Alireza K.; Baleanu, D.

    2016-08-01

    In this paper, we have generalized the Fα-calculus by suggesting Fourier and Laplace transformations of the function with support of the fractals set which are the subset of the real line. Using this generalization, we have found the diffraction fringes from the fractal grating Cantor sets.

  13. Effects of high fire frequency in creosote bush scrub vegetation of the Mojave Desert

    Science.gov (United States)

    Brooks, M.L.

    2012-01-01

    Plant invasions can increase fire frequency in desert ecosystems where fires were historically infrequent. Although there are many resource management concerns associated with high frequency fire in deserts, fundamental effects on plant community characteristics remain largely unstudied. Here I describe the effects of fire frequency on creosote bush scrub vegetation in the Mojave Desert, USA. Biomass of the invasive annual grass Bromus rubens L. increased following fire, but did not increase further with additional fires. In contrast, density, cover and species richness of native perennial plants each decreased following fire and continued to decrease with subsequent fires, although not as dramatically as after the initial fire. Responses were similar 5 and 14 years post-fire, except that cover of Hymenoclea salsola Torr. & A. Gray and Achnatherum speciosa Trin. & Rupr. both increased in areas burnt once. These results suggest that control of B. rubens may be equally warranted after one, two or three fires, but revegetation of native perennial plants is most warranted following multiple fires. These results are valid within the scope of this study, which is defined as relatively short term vegetation responses (???14 years) to short fire return intervals (6.3 and 7.3 years for the two and three fire frequency levels) within creosote bush scrub of the Mojave Desert. ?? 2012 IAWF.

  14. Recurrent fires and environment shape the vegetation in Quercus suber L. woodlands and maquis.

    Science.gov (United States)

    Schaffhauser, Alice; Curt, Thomas; Véla, Errol; Tatoni, Thierry

    2012-06-01

    The effects of fire recurrence on vegetation patterns in Quercus suber L. and Erica-Cistus communities in Mediterranean fire-prone ecosystems of south-eastern France were examined on stands belonging to 5 fire classes, corresponding to different numbers of fires (from 0 to 4) and time intervals between fires since 1959. A common pool of species was identified among the plots, which was typical of both open and closed maquis. Fire recurrence reduced the abundance of trees and herbs, whereas it increased the abundance of small shrubs. Richness differed significantly between the most contrasting classes of fire recurrence, with maximal values found in control plots and minimal values in plots that had burned recurrently and recently. Equitability indices did not vary significantly, in contrast to Shannon's diversity index which mostly correlated with richness. Forest ecosystems that have burnt once or twice in the last 50 years were resilient; that is to say they recovered a biomass and composition similar to that of the pre-fire state. However, after more than 3-4 fires, shrubland communities displayed lower species richness and diversity indices than unburned plots. The time since the last fire and the number of fires were the most explanatory fire variables, governing the structure of post-fire plant communities. However, environmental factors, such as slope or exposure, also made a significant contribution. Higher rates of fire recurrence can affect the persistence or expansion of shrublands in the future, as observed in other Mediterranean areas.

  15. Snow Cover Contributes to Post-fire Vegetation Regeneration in Mediterranean Climate Regions

    Science.gov (United States)

    Blauvelt, K. J.; Nolin, A. W.; Lintz, H. E.; Sproles, E. A.

    2012-12-01

    Predictions for the 21st century western United States climate include amplified fire regimes, earlier spring snowmelt and reduced snowpack. In the Pacific Northwest, burned area is projected to increase by as much as 300% by the end of this century. Continued declines in snowpack are also anticipated, especially at lower elevations. Previous research has established a link between declining snowpacks and wildfire. But what is the role of snow in the regeneration of vegetation after a fire? This investigation examines the relationship between post-fire vegetation and snowcover. We analyze the complex relationships between remotely sensed winter snow frequency and subsequent spring and summer vegetation biomass before and after large wildfires using a form of nonparametric multiplicative regression. We use snow cover and vegetation biomass data from the Moderate Resolution Imaging Spectroradiometer (MODIS). At each fire site, multiple physiographic predictor variables, (snow frequency, elevation, slope, aspect, vegetation type, and burn severity), are incorporated for the vegetation biomass response variable. For the Biscuit Fire (Klamath Mountains Ecoregion in SW Oregon), we see a negative correlation between winter snow frequency and subsequent spring EVI before the 2002 Biscuit Fire and a shift to a positive correlation after the fire during regeneration, while fires in other western ecoregions do not exhibit this shift. We also examine fire sites in the California Sierra Nevada and the Oregon Cascade Mountains. Snow cover frequency appears to be a valid predictor of post-fire biomass in climate regions where the summer dry period is relatively long. This research evaluates the relative importance of snowpack and other physiographic variables in post-fire vegetation regeneration across a latitudinal gradient of fire sites.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kruczek, H.; Raczka, P.; Tatarek, A. [Wroclaw Technical University, Wroclaw (Poland)

    2006-08-15

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

  17. Wildland Fire Safety

    Science.gov (United States)

    Wildland Fire Safety Every year, wildfires burn across the U.S., and more and more people are living where wildfires ... including garages and sheds. If it can catch fire, don’t let it touch your house, deck ...

  18. Filosofiens historiografi: Fire genrer

    DEFF Research Database (Denmark)

    Rorty, Richard

    2007-01-01

    Oversættelse af Richard Rortys artikel "Filosofiens historiografi: Fire genrer" Udgivelsesdato: 26 Oktober......Oversættelse af Richard Rortys artikel "Filosofiens historiografi: Fire genrer" Udgivelsesdato: 26 Oktober...

  19. Fire Stations - 2007

    Data.gov (United States)

    Kansas Data Access and Support Center — Fire Station Locations in Kansas Any location where fire fighters are stationed at or based out of, or where equipment that such personnel use in carrying out their...

  20. Coal fires in China

    Institute of Scientific and Technical Information of China (English)

    CHE Yao(车遥); HUANG Wen-hui(黄文辉); ZHANG Ai-yun(张爱云)

    2004-01-01

    Coal fires have a very long history in China; the oldest coal fires have being burning for many million years. Up to now more than 56 coal fires spots were distinguished. They mainly locate in West-North of China, North of China and East-North of China. About millions of tons of coal have been burned in fires every year. Xinjiang Autonomy is the most serious region in coal fires as it has 38 coal fires spots and about 6.85 million tons of coal was burned every year. Coal fires in China ignited by wildfires, spontaneous combustion and human being during mining activities. These fires have released about 0.9 million tons of gasses (including CO, CO2, SO2, NO2 CH4, CO2, H2S etc.) into the atmosphere every year, most of which are brought to the east by wind and resulting more heavier air pollution in northern China.