Science.gov

Sample records for biomass fired grate

  1. Chemical composition and physical properties of filter fly ashes from eight grate-fired biomass combustion plants.

    PubMed

    Lanzerstorfer, Christof

    2015-04-01

    For the handling, treatment and utilization of fly ash from biomass combustion its chemical composition and physical properties are important. In this study eight filter fly ashes from different grate-fired biomass combustion plants were investigated. In fly ash from straw combustion high concentrations of (K) were found, whereas in the fly ash from wood combustion the concentrations of Ca and Mg were higher. The average concentration of PO4(3-) was similar in both types of fly ashes. In all wood fly ashes some measured heavy metal concentrations were above the limits for utilization. The straw fly ashes were much less contaminated and can be utilized. For wood fly ash most parameters showed little variation, except from one fly ash where the dust pre-separator is in poor condition. The average values were: mass median diameter 4.3±0.8 μm, spread of particle size distribution 19±11, particle density 2620±80 kg/m3 and angle of repose 50°±1°. The density of the straw fly ashes is lower (2260±80 kg/m3) and the spread of the size distribution is higher (72±24). For one straw combustion fly ash the values of the mass median diameter and the angle of repose were similar to the values of wood combustion fly ash, for the other straw fly ash the values differed considerably. While the particle size of this fly ash was much smaller, surprisingly the angle of repose was also lower. This can be attributed to the formation of small agglomerates in this fly ash, which were not disintegrated without a certain stress. PMID:25872727

  2. Biomass externally fired gas turbine cogeneration

    SciTech Connect

    Eidensten, L.; Yan, J.; Svedberg, G.

    1996-07-01

    This paper is a presentation of a systematic study on externally fired gas turbine cogeneration fueled by biomass. The gas turbine is coupled in series with a biomass combustion furnace in which the gas turbine exhaust is used to support combustion. Three cogeneration systems have been simulated. They are systems without a gas turbine, with a non-top-fired gas turbine, and a top-fired gas turbine. For all systems, three types of combustion equipment have been selected: circulating fluidized bed (CFB) boiler, grate fired steam boiler, and grate fired hot water boiler. The sizes of biomass furnaces have been chosen as 20 MW and 100 MW fuel inputs. The total efficiencies based on electricity plus process heat, electrical efficiencies, and the power-to-heat ratios for various alternatives have been calculated. For each of the cogeneration systems, part-load performance with varying biomass fuel input is presented. Systems with CFB boilers have a higher total efficiency and electrical efficiency than other systems when a top-fired gas turbine is added. However, the systems with grate fired steam boilers allow higher combustion temperature in the furnace than CFB boilers do. Therefore, a top combustor may not be needed when high temperature is already available. Only one low-grade fuel system is then needed and the gas turbine can operate with a very clean working medium.

  3. Research on the fire alarming system of fiber grating

    NASA Astrophysics Data System (ADS)

    Qi, Yaobin

    2007-09-01

    The application of fiber grating sensing technology in fire alarming based on temperature detection has the advantages of high accuracy, high reliability and strong immunity from electronic and magnetic fields. It is especially advantageous to use this system in the petroleum and chemistry industry because it can provide an extraordinary safe means for the fire alarm. But due to the traditional optical Wavelength Division Multiplexing (WDM) technology is limited by the optic source bandwidth, the number of its multiplexing points is few. In this paper WDM technology will be developed mixing with Identified Bragg, which is called Identified and Wavelength Multiplexing, to build the Fiber Grating (FBG) fire alarm system integrated with computers. Some technologies applied in fire alarming system of fiber grating such as the transmission of test signals which pass through modulate and demodulate, the disposal of software system, the output of control signal and the strong ability of anti-disturbance have been studied and discussed.

  4. GASIFICATION BASED BIOMASS CO-FIRING

    SciTech Connect

    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 poultry litter

  5. Combustion characteristics and NO formation for biomass blends in a 35-ton-per-hour travelling grate utility boiler.

    PubMed

    Li, Zhengqi; Zhao, Wei; Li, Ruiyang; Wang, Zhenwang; Li, Yuan; Zhao, Guangbo

    2009-04-01

    Measurements were taken for a 35-ton-per-hour biomass-fired travelling grate boiler. Local mean concentrations of O(2), CO, SO(2) and NO gas species and gas temperatures were determined in the region above the grate. For a 28-ton-per-hour load, the mass ratios of biomass fly ash and boiler slag were 42% and 58%, the boiler efficiency was 81.56%, and the concentrations of NO(x) and SO(2) at 6% O(2) were 257 and 84 mg/m(3). For an 18-ton-per-hour load, the fuel burning zone was nearer to the inlet than it was for the 28-ton-per-hour load, and the contents of CO and NO in the fuel burning zone above the grate were lower. PMID:19091555

  6. Biomass Burning Emissions from Fire Remote Sensing

    NASA Technical Reports Server (NTRS)

    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.

  7. Selective Logging, Fire, and Biomass in Amazonia

    NASA Technical Reports Server (NTRS)

    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.

  8. [Emission characteristics of fine particles from grate firing boilers].

    PubMed

    Wang, Shu-Xiao; Zhao, Xiu-Juan; Li, Xing-Hua; Wei, Wei; Hao, Ji-Ming

    2009-04-15

    Grate firing boilers are the main type of Chinese industrial boilers, which accounts for 85% of the industrial boilers and is one of the most important emission sources of primary air pollutants in China. In this study, five boilers in three cities were selected and tested to measure the emission characteristics of PM2.5, and gaseous pollutants were applied by a compact dilution sampling system, which was developed for this field study. Results showed that particles mass size distributions for the five industrial boilers presented single peak or double peak, former peaks near 0.14 microm and the later peaks after 1.0 microm; the cyclone dust remover and wet scrubber dust remover had effective removal efficiencies not only to PM2.5, but also to PM1.0; and under the condition of same control techniques, grate firing boiler with high capacity has less PM2.5 emission than the boiler with low capacity. In the PM2.5 collected from flue gases, SO4(2-) was the most abundant ion, accounted for 20%-40% of the PM2.5; and C was the most abundant element (7.5%-31.8%), followed by S (8.4%-18.7%). Carbon balance method was applied to calculate the emission factors of these pollutants. The emission factors of PM2.5, NO, and SO2 were in the range of 0.046-0.486 g x kg(-1), 1.63-2.47 g x kg(-1), 1.35-9.95 g x kg(-1) respectively. The results are useful for the emission inventory development of industrial boilers and the source analysis of PM2.5 in atmospheric environment. PMID:19544990

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

    NASA Astrophysics Data System (ADS)

    Dzikuć, M.; Łasiński, K.

    2014-11-01

    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

  10. GASIFICATION BASED BIOMASS CO-FIRING - PHASE I

    SciTech Connect

    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.

  11. Carbon and Aerosol Emissions from Biomass Fires in Mexico

    NASA Astrophysics Data System (ADS)

    Hao, W. M.; Flores Garnica, G.; Baker, S. P.; Urbanski, S. P.

    2009-12-01

    Biomass burning is an important source of many atmospheric greenhouse gases and photochemically reactive trace gases. There are limited data available on the spatial and temporal extent of biomass fires and associated trace gas and aerosol emissions in Mexico. Biomass burning is a unique source of these gases and aerosols, in comparison to industrial and biogenic sources, because the locations of fires vary considerably both daily and seasonally and depend on human activities and meteorological conditions. In Mexico, the fire season starts in January and about two-thirds of the fires occur in April and May. The amount of trace gases and aerosols emitted by fires spatially and temporally is a major uncertainty in quantifying the impact of fire emissions on regional atmospheric chemical composition. To quantify emissions, it is necessary to know the type of vegetation, the burned area, the amount of biomass burned, and the emission factor of each compound for each ecosystem. In this study biomass burning experiments were conducted in Mexico to measure trace gas emissions from 24 experimental fires and wildfires in semiarid, temperate, and tropical ecosystems from 2005 to 2007. A range of representative vegetation types were selected for ground-based experimental burns to characterize fire emissions from representative Mexico fuels. A third of the country was surveyed each year, beginning in the north. The fire experiments in the first year were conducted in Chihuahua, Nuevo Leon, and Tamaulipas states in pine forest, oak forest, grass, and chaparral. The second-year fire experiments were conducted on pine forest, oak forest, shrub, agricultural, grass, and herbaceous fuels in Jalisco, Puebla, and Oaxaca states in central Mexico. The third-year experiments were conducted in pine-oak forests of Chiapas, coastal grass, and low subtropical forest on the Yucatan peninsula. FASS (Fire Atmosphere Sampling System) towers were deployed for the experimental fires. Each FASS

  12. Global Burned Area and Biomass Burning Emissions from Small Fires

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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 often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1-km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental-scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001-2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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 often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1-km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental-scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001-2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity

  14. Compacting biomass waste materials for co-firing with coal

    SciTech Connect

    Graham, J.; Kiesler, J.; Morgan, A.; Liu, H.; Marrero, T.R.

    1999-07-01

    The purpose of this study is to develop a process that allows for the optimum compaction of various biomass waste materials to form fuels that can be co-fired with coal in conventional coal-fired power plants. Previous studies have shown that the use of biomass fuels in conjunction with coal in power plants is beneficial for several reasons. The use of biomass fuels reduces the amount of harmful gases that are emitted into the atmosphere by the firing of coal alone. In addition, the biomass used is primarily waste products that would be placed in a municipal landfill. By using this waste material as a fuel, the volume of waste being disposed of in landfills can be decreased significantly. However, in an uncompacted state these biomass wastes are bulky and costly to handle and transport. Compacting the biomass will increase its density and decrease the difficulty in handling and shipping costs. Four biomass products, wood chips, sawdust, low quality waste paper, and tree trimmings were compacted at various pressures into 1.91-inch diameter logs. After compaction, the logs were subjected to ASTM standard tests for unconfined compressive strength and splitting tensile strength. Tumbling tests and drop tests were also performed according to ASTM standards. The logs were also subjected to a water absorption test. Finally, each log will be tested to determine its thermal characteristics, such as the heating value and the gases each log produces when burned.

  15. Potential of Co-firing of Woody Biomass in Coal Fired Power Plant

    NASA Astrophysics Data System (ADS)

    Makino, Yosuke; Kato, Takeyoshi; Suzuoki, Yasuo

    Taking the distributing woody biomass supply into account, this paper assesses the potential of a co-firing of woody biomass in utility's coal power plant from the both energy-saving and economical view points. Sawmill wastes, trimming wastes from fruit farms and streets, and thinning residues from forests in Aichi Prefecture are taken into account. Even though transportation energy is required, almost all of woody biomass can be more efficiently used in co-firing with coal than in a small-scale fuel cell system with gasification as a distributed utilization. When the capital cost of fuel cell system with 25% of total efficiency, including preprocess, gasification and power generation, is higher than 170× 103yen/kW, almost all of thinning residues can be more economically used in co-firing. The cost of woody biomass used in co-firing is also compared with the transaction cost of renewable power in the current RPS scheme. The result suggests the co-firing of woody biomass in coal fired power plant can be feasible measure for effective utilization of woody biomass.

  16. Biomass cofiring in full-sized coal-fired boilers

    SciTech Connect

    Plasynski, S.I.; Costello, R.; Hughes, E.; Tillman, D.

    1999-07-01

    Biomass cofiring represents one alternative for reducing greenhouse gas emissions of carbon dioxide from fossil sources. Realizing this opportunity, the Federal Energy Technology Center (FETC), a field site of the Department of Energy (DOE), along with the EPRI, initiated a Program around two-years ago to research the feasibility of coal-fired boilers in cofiring of biomass and other waste-derived fuels. The cooperative agreement between FETC and EPRI includes cofiring at six different electric utility sites and one steam generation site. Boilers include wall-fired, tangential, cyclone, and stokers ranging in size from 15 to 500 MWe. Biomass consisting of wood (usually) and switchgrass (in two cases) will be the fuel, and pulp and plastics may be used in some waste-derived fuels cofiring tests. This paper will focus only on the biomass cofired tests in electric utility boilers.

  17. FUEL LEAN BIOMASS REBURNING IN COAL-FIRED BOILERS

    SciTech Connect

    Jeffrey J. Sweterlitsch; Robert C. Brown

    2002-07-01

    This final technical report describes research conducted between July 1, 2000, and June 30, 2002, for the project entitled ''Fuel Lean Biomass Reburning in Coal-Fired Boilers,'' DOE Award No. DE-FG26-00NT40811. Fuel Lean Biomass Reburning is a method of staging fuel within a coal-fired utility boiler to convert nitrogen oxides (NOx) to nitrogen by creating locally fuel-rich eddies, which favor the reduction of NOx, within an overall fuel lean boiler. These eddies are created by injecting a supplemental fuel source, designated as the reburn fuel, downstream of the primary combustion zone. Chopped biomass was the reburn fuel for this project. Four parameters were explored in this research: the initial oxygen concentration ranged between 1%-6%, the amount of biomass used as the reburn fuel ranged between from 0%-23% of the total % energy input, the types of biomass used were low nitrogen switchgrass and high nitrogen alfalfa, and the types of carrier gases used to inject the biomass (nitrogen and steam). Temperature profiles and final flue gas species concentrations are presented in this report. An economic evaluation of a potential full-scale installation of a Fuel-Lean Biomass Reburn system using biomass-water slurry was also performed.

  18. Characterization of biomass burning aerosols from forest fire in Indonesia

    NASA Astrophysics Data System (ADS)

    Fujii, Y.; Iriana, W.; Okumura, M.; Lestari, P.; Tohno, S.; Akira, M.; Okuda, T.

    2012-12-01

    Biomass burning (forest fire, wild fire) is a major source of pollutants, generating an estimate of 104 Tg per year of aerosol particles worldwide. These particles have adverse human health effects and can affect the radiation budget and climate directly and indirectly. Eighty percent of biomass burning aerosols are generated in the tropics and about thirty percent of them originate in the tropical regions of Asia (Andreae, 1991). Several recent studies have reported on the organic compositions of biomass burning aerosols in the tropical regions of South America and Africa, however, there is little data about forest fire aerosols in the tropical regions of Asia. It is important to characterize biomass burning aerosols in the tropical regions of Asia because the aerosol properties vary between fires depending on type and moisture of wood, combustion phase, wind conditions, and several other variables (Reid et al., 2005). We have characterized PM2.5 fractions of biomass burning aerosols emitted from forest fire in Indonesia. During the dry season in 2012, PM2.5 aerosols from several forest fires occurring in Riau, Sumatra, Indonesia were collected on quartz and teflon filters with two mini-volume samplers. Background aerosols in forest were sampled during transition period of rainy season to dry season (baseline period). Samples were analyzed with several analytical instruments. The carbonaceous content (organic and elemental carbon, OC and EC) of the aerosols was analyzed by a thermal optical reflectance technique using IMPROVE protocol. The metal, inorganic ion and organic components of the aerosols were analyzed by X-ray Fluorescence (XRF), ion chromatography and gas chromatography-mass spectrometry, respectively. There was a great difference of chemical composition between forest fire and non-forest fire samples. Smoke aerosols for forest fires events were composed of ~ 45 % OC and ~ 2.5 % EC. On the other hand, background aerosols for baseline periods were

  19. Combined heat treatment and acid hydrolysis of cassava grate waste (CGW) biomass for ethanol production

    SciTech Connect

    Agu, R.C.; Amadife, A.E.; Ude, C.M.; Onyia, A.; Ogu, E.O.; Okafor, M.; Ezejiofor, E.

    1997-12-31

    The effect of combined heat treatment and acid hydrolysis (various concentrations) on cassava grate waste (CGW) biomass for ethanol production was investigated. At high concentrations of H{sub 2}SO{sub 4} (1--5 M), hydrolysis of the CGW biomass was achieved but with excessive charring or dehydration reaction. At lower acid concentrations, hydrolysis of CGW biomass was also achieved with 0.3--0.5 M H{sub 2}SO{sub 4}, while partial hydrolysis was obtained below 0.3 M H{sub 2}SO{sub 4} (the lowest acid concentration that hydrolyzed CGW biomass) at 120 C and 1 atm pressure for 30 min. A 60% process efficiency was achieved with 0.3 M H{sub 2}SO{sub 4} in hydrolyzing the cellulose and lignin materials present in the CGW biomass. High acid concentration is therefore not required for CGW biomass hydrolysis. The low acid concentration required for CGW biomass hydrolysis, as well as the minimal cost required for detoxification of CGW biomass because of low hydrogen cyanide content of CGW biomass would seem to make this process very economical. From three liters of the CGW biomass hydrolysate obtained from hydrolysis with 0.3M H{sub 2}SO{sub 4}, ethanol yield was 3.5 (v/v%) after yeast fermentation. However, although the process resulted in gainful utilization of CGW biomass, additional costs would be required to effectively dispose new by-products generated from CGW biomass processing.

  20. Particulate control system for biomass firing technologies

    SciTech Connect

    Easom, B.H.; Smolensky, L.A.; Wysk, S.R.

    1996-12-31

    The new particulate control equipment, the so-called Core Separator, overcomes most of the limitations inherent in conventional particulate control systems and can be effectively adapted for biomass applications. The Core Separator is a mechanical collector; however, this technology overcomes the performance limitation inherent in cyclones by performing the tasks of separation and collection in two separate components. The separation process is less affected by secondary flows and is much more efficient than the collection process. Also, the components of the system are arranged in such a way that the separation process determines the system efficiency. As a result, particulate emission rates downstream of this system are one fourth of those from the most efficient cyclones. This technology has been demonstrated through commercial unit installations in the U.S. and abroad. It has been used for industrial separations including coal fly ash, minerals, and chemical recovery applications. It is considered a lower-cost alternative to fabric filters and electrostatic precipitators, albeit one that can meet or exceed regulations for particulate emissions. Development of this technology has been funded by the U.S. Department of Energy, Environmental Protection Agency, and Electric Power Research Institute.

  1. Geostationary Fire Detection with the Wildfire Automated Biomass Burning Algorithm

    NASA Astrophysics Data System (ADS)

    Hoffman, J.; Schmidt, C. C.; Brunner, J. C.; Prins, E. M.

    2010-12-01

    The Wild Fire Automated Biomass Burning Algorithm (WF_ABBA), developed at the Cooperative Institute for Meteorological Satellite Studies (CIMSS), has a long legacy of operational wildfire detection and characterization. In recent years, applications of geostationary fire detection and characterization data have been expanding. Fires are detected with a contextual algorithm and when the fires meet certain conditions the instantaneous fire size, temperature, and radiative power are calculated and provided in user products. The WF_ABBA has been applied to data from Geostationary Operational Environmental Satellite (GOES)-8 through 15, Meteosat-8/-9, and Multifunction Transport Satellite (MTSAT)-1R/-2. WF_ABBA is also being developed for the upcoming platforms like GOES-R Advanced Baseline Imager (ABI) and other geostationary satellites. Development of the WF_ABBA for GOES-R ABI has focused on adapting the legacy algorithm to the new satellite system, enhancing its capabilities to take advantage of the improvements available from ABI, and addressing user needs. By its nature as a subpixel feature, observation of fire is extraordinarily sensitive to the characteristics of the sensor and this has been a fundamental part of the GOES-R WF_ABBA development work.

  2. Burned area, active fires and biomass burning - approaches to account for emissions from fires in Tanzania

    NASA Astrophysics Data System (ADS)

    Ruecker, Gernot; Hoffmann, Anja; Leimbach, David; Tiemann, Joachim; Ng'atigwa, Charles

    2013-04-01

    Eleven years of data from the globally available MODIS burned area and the MODS Active Fire Product have been analysed for Tanzania in conjunction with GIS data on land use and cover to provide a baseline for fire activity in this East African country. The total radiated energy (FRE) emitted by fires that were picked up by the burned area and active fire product is estimated based on a spatio-temporal clustering algorithm over the burned areas, and integration of the fire radiative power from the MODIS Active Fires product over the time of burning and the area of each burned area cluster. Resulting biomass combusted by unit area based on Woosteŕs scaling factor for FRE to biomass combusted is compared to values found in the literature, and to values found in the Global Fire Emissions Database (GFED). Pyrogenic emissions are then estimated using emission factors. According to our analysis, an average of 11 million ha burn annually (ranging between 8.5 and 12.9 million ha) in Tanzania corresponding to between 10 and 14 % of Tanzaniás land area. Most burned area is recorded in the months from May to October. The land cover types most affected are woodland and shrubland cover types: they comprise almost 70 % of Tanzania's average annual burned area or 6.8 million ha. Most burning occurs in gazetted land, with an annual average of 3.7 million ha in forest reserves, 3.3 million ha in game reserves and 1.46 million ha in national parks, totalling close to 8.5 million ha or 77 % of the annual average burned area of Tanzania. Annual variability of burned area is moderate for most of the analysed classes, and in most cases there is no clear trend to be detected in burned area, except for the Lindi region were annual burned area appears to be increasing. Preliminary results regarding emissions from fires show that for larger fires that burn over a longer time, biomass burned derived through the FRP method compares well to literature values, while the integration over

  3. The global Cretaceous-Tertiary fire: Biomass or fossil carbon

    NASA Technical Reports Server (NTRS)

    Gilmour, Iain; Guenther, Frank

    1988-01-01

    The global soot layer at the K-T boundary indicates a major fire triggered by meteorite impact. However, it is not clear whether the principal fuel was biomass or fossil carbon. Forests are favored by delta value of C-13, which is close to the average for trees, but the total amount of elemental C is approximately 10 percent of the present living carbon, and thus requires very efficient conversion to soot. The PAH was analyzed at Woodside Creek, in the hope of finding a diagnostic molecular marker. A promising candidate is 1-methyl-7-isopropyl phenanthrene (retene,), which is probably derived by low temperature degradation of abietic acid. Unlike other PAH that form by pyrosynthesis at higher temperatures, retene has retained the characteristic side chains of its parent molecule. A total of 11 PAH compounds were identified in the boundary clay. Retene is present in substantial abundance. The identification was confirmed by analysis of a retene standard. Retene is characteristic of the combustion of resinous higher plants. Its formation depends on both temperature and oxygen access, and is apparently highest in oxygen-poor fires. Such fires would also produce soot more efficiently which may explain the high soot abundance. The relatively high level of coronene is not typical of a wood combustion source, however, though it can be produced during high temperature pyrolysis of methane, and presumably other H, C-containing materials. This would require large, hot, low O2 zones, which may occur only in very large fires. The presence of retene indicates that biomass was a significant fuel source for the soot at the Cretaceous-Tertiary boundary. The total amount of elemental C produced requires a greater than 3 percent soot yield, which is higher than typically observed for wildfires. However, retene and presumably coronene imply limited access of O2 and hence high soot yield.

  4. The ELSAM strategy of firing biomass in CFB power plants

    SciTech Connect

    Rasmussen, I.; Clausen, J.C.

    1995-12-31

    The Danish power pool ELSAM has launched a program for developing a coal and biomass-fired CFB concept for future power plants, as an option to achieve a substantial reduction of CO{sub 2} emissions associated with energy generation. The general development of CFB technology abroad and domestic experience gained from small-scale coal and straw firing form the basis for this program. Since January 1992 MIDTKRAFT Power Company has been operating an 80 MWth CFB cogeneration plant located at Grenaa. This plant is fired with a mixture of hard coal and surplus straw from farming. The share of straw ranges from 0-60% on an energy basis. Straw contains much larger amounts of chlorine and potassium than normal fossil fuels, which implies a higher potential of superheater corrosion and combustor fouling. This paper reviews the experience gained during the first 3 years of operation of the CFB plant. The record includes early superheater corrosion and fouling incidents, a heat surface modification and its impact on subsequent plant operation. Apart from operational experience the paper will review the results of the R and D activities executed at the Grenaa plant for further CFB development. Based on the specific experience from Grenaa and the general evolution of the CFB technology ELSAM has initiated a program for development of a 250 MWe CFB power plant concept, firing up to 60% biomass (wood waste and a limited amount of annular crops). USC steam conditions are adopted for the novel concept, implying an expected plant efficiency of 45% (LHV-based). Special emphasis is attached to plant operational flexibility with a view to fulfilling general power plant requirements.

  5. Externally fired gas turbine cycles for small scale biomass cogeneration

    SciTech Connect

    Anheden, M.; Ahlroth, M.; Martin, A.R.; Svedberg, G.

    1999-07-01

    In this conceptual study, externally fired gas turbine cycles in combination with a biomass-fueled, atmospheric circulating fluidized bed (CFB) furnace are investigated for small scale heat and power production ({approximately} 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 power output. Aside from a thermodynamic performance analysis, the study also includes an evaluation of the turbomachinery characteristics. Simulation results show that thermodynamic performance varies slightly between the different configurations, with electrical efficiencies approaching 38% (LHV) and power-to-heat ratios as high as 0.80. Equipment size is found to depend primarily upon the type of working fluid.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

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

    2001-02-05

    The following are proposed activities for quarter 2 (9/15/00-12/14/00): (1) Conduct TGA and fuel characterization studies--Task 1; (2) Perform re-burn experiments--Task 2; (3) Fabricate fixed bed gasifier/combustor--Task 3; and (4) Modify the 3D combustion modeling code for feedlot and litter fuels--Task 4. The following were achieved During Quarter 2 (9/15/00-12/14/00): (1) The chicken litter has been obtained from Sanderson farms in Denton, after being treated with a cyclonic dryer. The litter was then placed into steel barrels and shipped to California to be pulverized in preparation for firing. Litter samples have also been sent for ultimate/proximate laboratory analyses.--Task 1; (2) Reburn-experiments have been conducted on coal, as a base case for comparison to litter biomass. Results will be reported along with litter biomass as reburn fuel in the next report--Task 2; (3) Student has not yet been hired to perform task 3. Plans are ahead to hire him or her during quarter No. 3; and (4) Conducted a general mixture fraction model for possible incorporation in the code.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Biomass Combustions and Burning Emissions Inferred from GOES Fire Radiative Power

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Kondragunta, S.; Schmidt, C.

    2007-12-01

    Biomass burning significantly affects air quality and climate changes. Current estimates of burning emissions are rather imprecise and vary markedly with different methodologies. This paper investigates biomass burning consumption and emissions using GOES (Geostationary Operational Environmental Satellites) WF_ABBA (Wildfire Automated Biomass Burning Algorithm) fire product. In doing this, we establish a set of representatives in diurnal patterns of half-hourly GOES Fire Radiative Power (FRP) for various ecosystems. The representative patterns are used to fill the missed and poor observations of half hourly FRP in GOES fire data for individual fire pixels. The simulated FRP is directly applied to the calculation of the biomass combusted during fire activities. The FRP-based biomass combustion is evaluated using the estimates using a traditional model which integrates burned area, fuel loading, and combustion factor. In the traditional model calculation, we derive burned areas from GOES WF_ABBA fire size. Fuel loading includes three different types (1) MODIS Vegetation Property-based Fuel System (MVPFS), (2) National Dangerous Rating Systems (NFDRS), and (3) the Fuel Characteristic Classification System (FCCS). By comparing the biomass combustions across the Contiguous United States (CONUS) from 2003-2005, we conclude that FRP is an effective tool to estimate the biomass burning emissions. Finally, we examine the temporal and spatial patterns in biomass combustions and emissions (PM2.5, CO, NH3) across the CONUS.

  10. A supply chain network design model for biomass co-firing in coal-fired power plants

    SciTech Connect

    Md. S. Roni; Sandra D. Eksioglu; Erin Searcy; Krishna Jha

    2014-01-01

    We propose a framework for designing the supply chain network for biomass co-firing in coal-fired power plants. This framework is inspired by existing practices with products with similar physical characteristics to biomass. We present a hub-and-spoke supply chain network design model for long-haul delivery of biomass. This model is a mixed integer linear program solved using benders decomposition algorithm. Numerical analysis indicates that 100 million tons of biomass are located within 75 miles from a coal plant and could be delivered at $8.53/dry-ton; 60 million tons of biomass are located beyond 75 miles and could be delivered at $36/dry-ton.

  11. Doubling of the Russian Fire Return Interval: Implications for Forest Biomass and Composition

    NASA Astrophysics Data System (ADS)

    Shuman, J. K.; Foster, A.; Shugart, H. H., Jr.; Hoffman-Hall, A.; Loboda, T. V.

    2015-12-01

    The Russian boreal forest has experienced significant warming over the past several decades and this trend is expected to continue. This warming has the capacity to alter dominant vegetation and biomass dynamics through shifts in competition dynamics, a change in treeline and an increased fire disturbance regime. Historical fire return interval is calculated for the Russian ecoregions and applied to 31,010 points of a 22 x 22 km2 grid. Using an individual tree based forest gap model, UVAFME, biomass and species dynamics are simulated for multiple scenarios: without fire, with historical fire probabilities, a doubling of probabilities across the region, and the combined effect of fire with an altered climate. Fire disturbance within the model is a randomly occurring event with a variable intensity that alters the seedling bank and kills trees according to unique species fire tolerance parameters. Results from the simulation scenarios are compared to assess changes in biomass, species composition, and age structure 500 years after bare ground initiation. At the end of simulation, results which include fire disturbance show an increase in biomass across the region compared to simulation without fire. This increase in biomass in the simulations with fire disturbance is associated with an overall decrease in the age of the forest to younger more productive stands. The doubling of the fire return interval maintains a higher percentage of the needle leaf deciduous larch across Siberia. With altered climate, the region experiences an overall decrease in biomass and a shift in composition towards early successional deciduous species. These results reinforce the importance of the inclusion of complex competition and age structure in evaluating forest response to disturbance and changing climate.

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

    PubMed

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

    2014-06-24

    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. PMID:24963094

  13. Intercomparison of Near-Real-Time Biomass Burning Emissions Estimates Constrained by Satellite Fire Data

    EPA Science Inventory

    We compare biomass burning emissions estimates from four different techniques that use satellite based fire products to determine area burned over regional to global domains. Three of the techniques use active fire detections from polar-orbiting MODIS sensors and one uses detec...

  14. Estimating Root Biomass and Distribution After Fire in a Great Basin Woodland Using Cores or Pits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurately estimating root biomass is critically important for understanding how below ground carbon storage is affected by different plant life forms and by fire. We compared a new soil coring technique with traditional quantitative pits for determining root biomass. We conducted the study in an ex...

  15. Co-firing of coal and biomass advantages and problems

    SciTech Connect

    Kartak, J.; Pichal, M.; Benes, I.

    1996-12-31

    Biomass power belongs to the viable contenders for new generation sources. Biomass power already accounts for about 12% of world primary energy consumption. In the Czech Republic, this fraction makes several tenths of percent, although it is realistic to increase it up to 4 or 6%. The great difference between the large potential of energetic biomass exploitation and current utilization status shows the necessity to examine the reasons of low biomass usage.

  16. Recovery of plant biomass and soil N cycling in Alaskan tundra following an unusual fire

    NASA Astrophysics Data System (ADS)

    Bret-Harte, M. S.; Mack, M. C.; Huebner, D. C.; Johnston, M.; Shaver, G. R.

    2012-12-01

    Climate warming is likely to increase the frequency of disturbances in the Arctic. The Anaktuvuk River fire of 2007 burned 1039 km2 of northern Alaskan tundra; this was unprecedented for this vegetation, which is clonal, slow-growing, and long-lived. We harvested plant biomass and soils from severely and moderately burned areas and controls in 2011 to assess recovery of plant productivity and soil N cycling four years after the fire. Biomass of vascular plants had recovered to nearly control levels in moderately burned areas, due primarily to resprouting by graminoids, particularly Eriophorum vaginatum. Graminoid biomass was actually greater in moderately burned tundra than in unburned tundra. Deciduous shrub and evergreen shrub biomass in moderately burned tundra was approximately half that seen in unburned tundra, but non-vascular plant biomass was much less, so that total aboveground biomass in moderately burned tundra had not returned to control levels. Severely burned tundra had less of all components of the community than in moderately burned tundra, except that there was higher biomass of non-vascular plants, due to colonization by fire-following liverworts and mosses. Productivity of vascular plants was similar in unburned and severely burned tundra plots, and higher in moderately burned plots, due in part to higher soil N availability. Recovery of plant biomass was largely due to resprouting of species that survived the fire, though numerous seedlings were seen. Biomass of vascular plants has recovered rapidly in the moderately burned sites, while severely burned sites and nonvascular plants are recovering more slowly, but the relative abundance of different species differs from unburned tundra. The relationship between spectral indices (NDVI, EVI-2) collected at the plot level and either biomass or NPP varied with burn category, which may complicate assessments of NPP by remote sensing following fire.

  17. Production of CO{sub 2}, CO and hydrocarbons from biomass fires

    SciTech Connect

    Hao, W.M.; Ward, D.E.; Olbu, G.

    1995-12-01

    Emissions of CO{sub 2}, CO, CH{sub 4}, C{sub 2}-C{sub 6} alkanes and alkenes, and aromatic compounds from various biomass fires have been quantified. These gases play important roles in tropospheric chemistry, stratospheric chemistry, and global climate. The fires were used for deforestation and shifting cultivation in tropical forests and for growth of fresh grass in tropical savannas. Smoke samples were collected in stainless steel canisters and were analyzed by gas chromatographs with flame ionization detectors. We investigate and compare the differences in the combustion efficiency, the emission factor of each compound, and the relationship among emitted compounds between forest and savanna fires. The contributions of biomass burning to the sources of these gases in the atmosphere are estimated. We will also assess the potential impact of biomass fires on changes in atmospheric chemistry and global climate.

  18. The GOES-R ABI Wild Fire Automated Biomass Burning Algorithm

    NASA Astrophysics Data System (ADS)

    Hoffman, J.; Schmidt, C. C.; Prins, E. M.; Brunner, J. C.

    2011-12-01

    The global Wild Fire Automated Biomass Burning Algorithm (WF_ABBA) at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) provides fire detection and characterization using data from a global constellation of geostationary satellites, currently including GOES, MTSAT, and Meteosat. CIMSS continues to enhance the legacy of the WF_ABBA by adapting the algorithm to utilize the advanced spatial, spectral, and temporal capabilities of GOES-R ABI. A wide range of simulated ABI data cases have been generated and processed with the GOES-R fire detection and characterization algorithm. Simulated cases included MODIS derived projections as well as model derived simulations that span a variety of satellite zenith angles and ecosystems. The GOES-R ABI fire product development focuses on active fire detection and sub-pixel characterization, including fire radiative power (FRP) and instantaneous fire size and temperature. With the algorithm delivered to the system contractor, the focus has moved to developing innovative new validation techniques.

  19. Fuel biomass and combustion factors associated with fires in savanna ecosystems of South Africa and Zambia

    NASA Astrophysics Data System (ADS)

    Shea, Ronald W.; Shea, Barbara W.; Kauffman, J. Boone; Ward, Darold E.; Haskins, Craig I.; Scholes, Mary C.

    1996-10-01

    Fires are dominant factors in shaping the structure and composition of vegetation in African savanna ecosystems. Emissions such as CO2, NOx, CH4, and other compounds originating from these fires are suspected to contribute substantially to changes in global biogeochemical processes. Limited quantitative data exist detailing characteristics of biomass, burning conditions, and the postfire environment in African savannas. Fourteen test sites, differentiated by distinct burn frequency histories and land-use patterns, were established and burned during August and September 1992 in savanna parklands of South Africa and savanna woodlands of Zambia. Vegetation physiognomy, available fuel loads, the levels of biomass consumed by fire, environmental conditions, and fire behavior are described. In the South African sites, total aboveground fuel loads ranged from 2218 to 5492 kg ha-1 where fire return intervals were 1-4 years and exceeded 7000 kg ha-1 at a site subjected to 38 years of fire exclusion. However, fireline intensity was only 1419 kW m-1 at the fire exclusion site, while ranging from 480 to 6130 kW m-1 among the frequent fire sites. In Zambia, total aboveground fuel loads ranged from 3164 kg ha-1 in a hydromorphic grassland to 7343 kg ha-1 in a fallow shifting cultivation site. Dormant grass and litter constituted 70-98% of the total fuel load among all sites. Although downed woody debris was a relatively minor fuel component at most sites, it constituted 43-57% of the total fuel load in the fire exclusion and shifting cultivation sites. Fire line intensity ranged between 1734 and 4061 kW m-1 among all Zambian sites. Mean grass consumption generally exceeded 95%, while downed woody debris consumption ranged from 3 to 73% at all sites. In tropical savannas and savanna woodlands of southern Africa, differences in environmental conditions, land- use patterns, and fire regimes influence vegetation characteristics and thus influence fire behavior and biomass

  20. Evaluating the coupled vegetation-fire model, LPJ-GUESS-SPITFIRE, against observed tropical forest biomass

    NASA Astrophysics Data System (ADS)

    Spessa, Allan; Forrest, Matthew; Werner, Christian; Steinkamp, Joerg; Hickler, Thomas

    2013-04-01

    Wildfire is a fundamental Earth System process. It is the most important disturbance worldwide in terms of area and variety of biomes affected; a major mechanism by which carbon is transferred from the land to the atmosphere (2-4 Pg per annum, equiv. 20-30% of global fossil fuel emissions over the last decade); and globally a significant source of particulate aerosols and trace greenhouse gases. Fire is also potentially important as a feedback in the climate system. If climate change favours more intense fire regimes, this would result in a net transfer of carbon from ecosystems to the atmosphere, as well as higher emissions, and under certain circumstances, increased troposphere ozone production- all contributing to positive climate-land surface feedbacks. Quantitative analysis of fire-vegetation-climate interactions has been held back until recently by a lack of consistent global data sets on fire, and by the underdeveloped state of dynamic vegetation-fire modelling. Dynamic vegetation-fire modelling is an essential part of our forecasting armory for examining the possible impacts of climate, fire regimes and land-use on ecosystems and emissions from biomass burning beyond the observation period, as part of future climate or paleo-climate studies. LPJ-GUESS is a process-based model of vegetation dynamics designed for regional to global applications. It combines features of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) with those of the General Ecosystem Simulator (GUESS) in a single, flexible modelling framework. The models have identical representations of eco-physiological and biogeochemical processes, including the hydrological cycle. However, they differ in the detail with which vegetation dynamics and canopy structure are simulated. Simplified, computationally efficient representations are used in the LPJ-DGVM, while LPJ-GUESS employs a gap-model approach, which better captures ecological succession and hence ecosystem changes due to

  1. Early post-fire succession in California chaparral: Changes in diversity, density, cover and biomass

    USGS Publications Warehouse

    Guo, Q.

    2001-01-01

    For four consecutive years, following the fires in November 1993, temporal variations in species richness, cover and biomass of component plant groups in early post-fire chaparral succession were monitored on different aspects at the Stunt Ranch Santa Monica Mountains Reserve, southern California. Plant groups were categorized based on growth form, life form, ability to fix nitrogen, geographic origin and regeneration strategies. North-facing slopes exhibited higher species richness, higher species turnover rate over time and faster vegetation recovery in terms of biomass accumulation and return to pre-fire species composition. This was probably due to higher species richness and biomass of nitrogen-fixing species found on north-facing slopes in comparison to south-facing slopes. On both north- and south-facing slopes, annuals had the highest species turnover rate, followed by herbaceous perennials and shrubs. In the first four post-fire years, annual species were the largest floristic group, but herbaceous perennials and shrubs were the major contributors to community biomass. Nitrogen-fixing species and exotics contributed significantly to early post-fire community structure. Although the general trends in post-fire succession are clear in terms of temporal changes in the relative proportions of different plant groups, environmental variation and the nature of plant life histories of component species, especially dominant species, could alter such trends significantly.

  2. Early post-fire succession in California chaparral: changes in diversity, density, cover, and biomass

    USGS Publications Warehouse

    Guo, Q.

    2001-01-01

    For four consecutive years, following the fires in November 1993, temporal variations in species richness, cover and biomass of component plant groups in early post-fire chaparral succession were monitored on different aspects at the Stunt Ranch Santa Monica Mountains Reserve, southern California. Plant groups were categorized based on growth form, life form, ability to fix nitrogen, geographic origin and regeneration strategies. North-facing slopes exhibited higher species richness, higher species turnover rate over time and faster vegetation recovery in terms of biomass accumulation and return to pre-fire species composition. This was probably due to higher species richness and biomass of nitrogen-fixing species found on north-facing slopes in comparison to south-facing slopes. On both north- and south-facing slopes, annuals had the highest species turnover rate, followed by herbaceous perennials and shrubs. In the first four post-fire years, annual species were the largest floristic group, but herbaceous perennials and shrubs were the major contributors to community biomass. Nitrogen-fixing species and exotics contributed significantly to early post-fire community structure. Although the general trends in post-fire succession are clear in terms of temporal changes in the relative proportions of different plant groups, environmental variation and the nature of plant life histories of component species, especially dominant species, could alter such trends significantly.

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

    SciTech Connect

    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.

  4. Measurement of electrical conductivity for a biomass fire.

    PubMed

    Mphale, Kgakgamatso; Heron, Mal

    2008-08-01

    A controlled fire burner was constructed where various natural vegetation species could be used as fuel. The burner was equipped with thermocouples to measure fuel surface temperature and used as a cavity for microwaves with a laboratory quality 2-port vector network analyzer to determine electrical conductivity from S-parameters. Electrical conductivity for vegetation material flames is important for numerical prediction of flashover in high voltage power transmission faults research. Vegetation fires that burn under high voltage transmission lines reduce flashover voltage by increasing air electrical conductivity and temperature. Analyzer determined electrical conductivity ranged from 0.0058 - 0.0079 mho/m for a fire with a maximum temperature of 1240 K. PMID:19325812

  5. Measurement of Electrical Conductivity for a Biomass Fire

    PubMed Central

    Mphale, Kgakgamatso; Heron, Mal

    2008-01-01

    A controlled fire burner was constructed where various natural vegetation species could be used as fuel. The burner was equipped with thermocouples to measure fuel surface temperature and used as a cavity for microwaves with a laboratory quality 2-port vector network analyzer to determine electrical conductivity from S-parameters. Electrical conductivity for vegetation material flames is important for numerical prediction of flashover in high voltage power transmission faults research. Vegetation fires that burn under high voltage transmission lines reduce flashover voltage by increasing air electrical conductivity and temperature. Analyzer determined electrical conductivity ranged from 0.0058 - 0.0079 mho/m for a fire with a maximum temperature of 1240 K. PMID:19325812

  6. Market potential for biomass co-fire in the four corners region

    SciTech Connect

    Whittier, J.; Haase, S.; Lynch, D.L.

    1996-12-31

    Fire suppression and heavy logging have caused major ecological changes in the pine forests of the San Juan-Rio Grande National Forest. A demonstration and administrative study sale was offered to determine the potential for ecosystem restoration in the forest. The conditions of the sale required the removal of trees from designated units that are typically classified as either Products Other than Logs (POL) or non-merchantable timber in addition to sawtimber. There are approximately 3.7 GW (net) of coal-fired power production capacity within 100 miles of the SJNF. Co-firing of biofuels with fossil fuels has significant potential for utility-scale power production. However, the economics and technical feasibility of co-firing are site-specific, depending on issues such as the availability of biomass, plant layout, existing combustion system technology, and the current cost of coal. The results of the feasibility analysis suggest limited market potential for forestry residues in area power plants. High biomass costs, despite USFS subsidies, coupled with low coal costs and coal supplier issues hinder the prospects for biomass co-fire opportunities. environmental considerations associated with reduced emissions (SO{sub x}, NO{sub x}, CO{sub 2}) are not major issues because of low sulfur coal that is widely available and limited markets for NO{sub x} and CO{sub 2} reductions.

  7. Potentials of Biomass Co-Combustion in Coal-Fired Boilers

    NASA Astrophysics Data System (ADS)

    Werther, J.

    The present work provides a survey on the potentials of co-combustion of biomass and biogenic wastes in large-scale coal-fired power plants. This allows an energetic utilization at a high level of efficiency which is not obtainable in small-scale dedicated biomass combustors. Co-firing at low percentages of the thermal power (typically below 5-10 %) avoids the characteristic operating problems of biomass combustion, i.e. ash sintering and fouling of heat transfer surfaces. Co-firing of biogenic wastes is already widely practiced in Germany, non-waste biomass like forest residues are for subsidy reasons combusted in small dedicated mono-combustion plants. A future increase of co-combustion may be associated with the upgrading of biogenic wastes with high water content to biofuels by drying. Such biofuels could substitute more expensive coal and save on CO2 emission certificates. In the more distant future biomass co-combustion may help in the CO2 scrubbing process by lowering the target level of CO2 absorption efficiency.

  8. Regional biomass burning trends in India: Analysis of satellite fire data

    NASA Astrophysics Data System (ADS)

    Sahu, L. K.; Sheel, Varun; Pandey, Kumud; Yadav, Ravi; Saxena, P.; Gunthe, Sachin

    2015-10-01

    The results based on the analysis of satellite fire counts detected by the Along-Track Scanning Radiometer (ATSR) sensors over different regions of India during 1998-2009 have been presented. Generally, the activities of open biomass burning show large spatial and temporal variations in India. The highest and lowest values of monthly fire counts were detected during the periods of March-May and July-September, respectively over different regions of India. The activities of biomass burning in two central states of Madhya Pradesh and Maharashtra were the highest and together accounted for about 25-45% of total annual fire counts detected over India during the study period. However, in opposite phases, the rainfall and fire count data show strong seasonal variation. In addition to large regional and seasonal variations, the fire data also show significant year-to-year variation. The higher annual fire counts exceeding the mean of entire period by about 16% and 43% were detected during the two periods of 1998-2000 and 2007-2009, respectively. We have estimated normalized anomaly of annual fire count data which shows large positive departures from long-term mean for the years 1999, 2007, 2008 and 2009, while negative departures for the years 2002, 2003 and 2005. Consistently, the mixing ratio of carbon monoxide (CO) typical peaks during winter but extended to pre-monsoon season during extensive fire years. The annual data over the entire region of India show lesser positive trend of about 3% yr-1. The inter-annual variation of fire count over entire India follows the trend in the ENSO Precipitation Index (ESPI) but shows opposite trend to the multivariate ENSO Index (MEI).

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

    NASA Astrophysics Data System (ADS)

    Prasad Vadrevu, Krishna; Lasko, Kristofer; Giglio, Louis; Justice, Chris

    2015-10-01

    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.

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

    SciTech Connect

    Unknown

    2002-07-01

    Proposed activities for quarter 8 (3/15/2001--6/14/2002), Boiler Burner Simulation and Experiments: (1) Continue the parametric study of cofiring of pulverized coal and LB in the boiler burner, and determining the combustor performance and emissions of NO, CO, CO{sub 2}, PO{sub 2} and P{sub 4}O{sub 10}, etc. The air-fuel ratio, swirl number of the secondary air stream and moisture effects will also be investigated (Task 4). Gasification: (Task 3) (2) Measuring the temperature profile for chicken litter biomass under different operating conditions. (3) Product gas species for different operating conditions for different fuels. (4) Determining the bed ash composition for different fuels. (5) Determining the gasification efficiency for different operating conditions. Activities Achieved during quarter 8 (3/15/2001--6/14/2002), Boiler Burner Simulation and Experiments: (1) The evaporation and phosphorus combustion models have been incorporated into the PCGC-2 code. Mr. Wei has successfully defended his Ph.D. proposal on Coal: LB modeling studies (Task 4, Appendix C). (2) Reburn experiments with both low and high phosphorus feedlot biomass has been performed (Task 2, Appendix A). (3) Parametric studies on the effect of air-fuel ratio, swirl number of the secondary air stream and moisture effects have been investigated (Task 2, Appendix A). (4) Three abstracts have been submitted to the American Society of Agricultural Engineers Annual International meeting at Chicago in July 2002. Three part paper dealing with fuel properties, cofiring, large scale testing are still under review in the Journal of Fuel. Gasification: (Task 3, Appendix B) (5) Items No. 2, and 3 are 95% complete, with four more experiments yet to be performed with coal and chicken litter biomass blends. (6) Item No. 4, and 5 shall be performed after completion of all the experiments.

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

    SciTech Connect

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

    2001-05-10

    The following are proposed activities for quarter 3 (12/15/00-3/14/01): (1) Conduct TGA and fuel characterization studies - Task 1; (2) Continue to perform re-burn experiments. - Task 2; (3) Design fixed bed combustor. - Task 3; and (4) Modify the PCGC2 code to include moisture evaporation model - Task 4. The following were achieved During Quarter 3 (12/15/0-3/14/01): (1) Conducted TGA and Fuel Characterization studies (Appendix I). A comparison of -fuel properties, TGA traces etc is given in Appendix I. Litter has 3 and 6 times more N compared to coal on mass and heat basis. The P of litter is almost 2 % (Task 1). Both litter biomass (LB) and feedlot biomass (FB) have been pulverized. The size distributions are similar for both litter and FB in that 75 % pass through 150 {micro}m sieve while for coal 75 % pass through 60 {micro}m sieve. Rosin Rammler curve parameters are given. The TGA characteristics of FB and LB are similar and pyrolysis starts at 100 C below that of coal; (2) Reburn experiments with litter and with FB have been performed (Appendix II) -Task 2. Litter is almost twice effective (almost 70--90 % reduction) compared to coal in reducing the NOx possibly due to presence of N in the form of NH{sub 3}; (3) Designed fixed bed gasifier/combustor (Appendix III) - Task 3; and (4) Modified PCGC2 to include moisture evaporation model in coal and biomass particles. (Appendix IV) - Task 4.

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

    NASA Astrophysics Data System (ADS)

    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

  13. Forest Fire Burned Biomass Estimation Using Satellite Images and Reference Data

    NASA Astrophysics Data System (ADS)

    Qin, Xianlin; Zu, Xiaofeng; Deng, Guang; Li, Zengyuan; Zhang, Zihui; Casanova, J. L. Sanz, Julia; Salvador, Pablo

    2014-11-01

    Vegetation biomass burning has been identified as a significant source of aerosols, carbon fluxes, and trace gases, which pollute the atmosphere and contribute to radiative forcing responsible for global climate change. To estimate the total biomass burned by forest fire using satellite images in Dragon 3, basing on the fuel load from reference data,the combustion factor getting from fieldwork at the sub-compartment level, and the results of burned scar mapping by using HJ-1A CCD and the monthly MODIS burned production datasets (MCD45A1), the biomass burned of the selected experiment area has been estimated by combining these data. The result showed that the accuracy of the biomass burned estimation mainly was affected by the accuracy of burned scar edge using the spatial resolution of satellite data.

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

    SciTech Connect

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Soyuz Priyadarsan

    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 four conference

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

    SciTech Connect

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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

  18. Regional biomass fired power plant siting Wisconsin project

    SciTech Connect

    Smith, M.L.

    1996-12-31

    The use of alternative fuels such as wood chips, wood products industry residues, refuse derived fuel, tire derived fuel and processed manufacturing paper waste fuel pellets has been practiced for a number of years in the state of Wisconsin. At present a relatively small quantity of the non-forestry urban wood waste is reclaimed for a variety of uses such as architectural mulch, animal bedding, nature trails in parks and recreational areas. Most is disposed of by landfills. This wood waste has low bulky density, depletes valuable landfill space, and in the Milwaukee area, currently costs $35-$50 per ton for hauling and disposal. This paper reviews the technical and economic feasibility of processing urban wood wastes using existing scrap processing facilities and transporting and supplying the wood fuel to existing stream and power generating facilities at state of Wisconsin institutions. The paper is based on a recent study funded by The Great Lakes Regional Biomass Energy Program. The capability of a large midwest auto shredding/scrap processing facility, one of 200 such facilities in the US, to serve as a central urban waste fuels processor is reviewed.

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

    NASA Astrophysics Data System (ADS)

    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

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

    SciTech Connect

    Nichol, Corrie Ian

    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).

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Technical Reports Server (NTRS)

    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

  3. Global Characterization of Biomass-Burning Patterns using Satellite Measurements of Fire Radiative Energy

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Giglio, Louis; Wooster, Martin J.; Remer, Lorraine A.

    2008-01-01

    Remote sensing is the most practical means of measuring energy release from large open-air biomass burning. Satellite measurement of fire radiative energy (FRE) release rate or power (FRP) enables distinction between fires of different strengths. Based on a 1-km resolution fire data acquired globally by the MODerate-resolution Imaging Spectro-radiometer (MODIS) sensor aboard the Terra and Aqua satellites from 2000 to 2006, instanteaneous FRP values ranged between 0.02 MW and 1866 MW, with global daily means ranging between 20 and 40 MW. Regionally, at the Aqua-MODIS afternoon overpass, the mean FRP values for Alaska, Western US, Western Australia, Quebec and the rest of Canada are significantly higher than these global means, with Quebec having the overall highest value of 85 MW. Analysis of regional mean FRP per unit area of land (FRP flux) shows that a peak fire season in certain regions, fires can be responsible for up to 0.2 W/m(sup 2) at peak time of day. Zambia has the highest regional monthly mean FRP flux of approximately 0.045 W/m(sup 2) at peak time of day and season, while the Middle East has the lowest value of approximately 0.0005 W/m(sup 2). A simple scheme based on FRP has been devised to classify fires into five categories, to facilitate fire rating by strength, similar to earthquakes and hurricanes. The scheme uses MODIS measurements of FRP at 1-km resolution as follows: catagory 1 (less than 100 MW), category 2 (100 to less than 500 MW), category 3 (500 to less than 1000 MW), category 4 (1000 to less than 1500 MW), catagory 5 (greater than or equal to 1500 MW). In most regions of the world, over 90% of fires fall into category 1, while only less than 1% fall into each of categories 3 to 5, although these proportions may differ significantly from day to day and by season. The frequency of occurence of the larger fires is region specific, and could not be explained by ecosystem type alone. Time-series analysis of the propertions of higher category

  4. Effects of fire on composition, biomass, and nutrients in oak scrub vegetation on John F. Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.; Hinkle, C. Ross

    1987-01-01

    Four stands of oak scrub two, four, eight, and 25 years since fire were sampled with permanent 15 m line transects. Percent cover by species was determined. Plant samples were analyzed for a variety of substances. Transects were resurveyed in 1985 for vegetation parameters. Nutrient pools in biomass were calculated from biomass data and tissue nutrient concentrations. Soil nutrient pools were calculated from nutrient concentrations and bulk density. Species distribution and soil chemical properties were found to be closely related to water table depth. The following fire-related conclusions are reached: (1) major structural changes occur in scrub after fire in that shrub height is reduced and requires four to six years to exceed 1 m; (2) reduction in shrub height affects the suitability of scrub for the Florida scrub jay (3) live biomass increases with time since fire; (4) nutrient concentrations in live biomass do not change with time since fire; (5) species composition and richness are little changed after fire; and (6) imposition of a continued regime of burning on a three-year cycle may have adverse impacts not indicated by the recovery of scrub from a single fire.

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

    SciTech Connect

    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

  6. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    SciTech Connect

    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

  7. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    SciTech Connect

    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

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

    SciTech Connect

    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

  9. Properties and evolution of biomass burning organic aerosol from Canadian boreal forest fires

    NASA Astrophysics Data System (ADS)

    Jolleys, M. D.; Coe, H.; McFiggans, G.; Taylor, J. W.; O'Shea, S. J.; Le Breton, M.; Bauguitte, S. J.-B.; Moller, S.; Di Carlo, P.; Aruffo, E.; Palmer, P. I.; Lee, J. D.

    2014-10-01

    Airborne measurements of biomass burning organic aerosol (BBOA) from boreal forest fires reveal highly contrasting properties for plumes of different ages. These measurements, performed using an Aerodyne Research Inc. compact time-of-flight aerosol mass spectrometer (C-ToF-AMS) during the BORTAS (quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment in the summer of 2011, have been used to derive normalised excess organic aerosol (OA) mass concentrations (ΔOA/ΔCO), with higher average ratios observed closer to source (0.190 ± 0.010) than in the far-field (0.097 ± 0.002). The difference in ΔOA/ΔCO between fresh and aged plumes is influenced by a change in dominant combustion conditions throughout the campaign. Measurements at source sampled largely smouldering fires, while plumes encountered in the far-field originated from fires occurring earlier in the campaign when fire activity had been more intense. Changing combustion conditions also affect the vertical distribution of biomass burning emissions, as aged plumes from more flaming-dominated fires are injected to higher altitudes of up to 6000 m. Proportional contributions of the mass-to-charge ratio (m/z) 60 and 44 peaks in the AMS mass spectra to the total OA mass (denoted f60 and f44) are used as tracers for primary and oxidized BBOA, respectively. Given the shorter aging times associated with near-field plumes, f44 is lower on average than in more aged, transported plumes. However, high levels of ΔO3/ΔCO and -log(NOx/NOy) close to source indicate that emissions can be subject to very rapid oxidation over short timescales. Conversely, the lofting of plumes into the upper troposphere can lead to the retention of source profiles after transportation over extensive temporal and spatial scales, with f60 also higher on average in aged plumes. Evolution of OA composition with aging is comparable to observations of BB tracers in

  10. Particle size distributions from laboratory-scale biomass fires using fast response instruments

    NASA Astrophysics Data System (ADS)

    Hosseini, S.; Li, Q.; Cocker, D.; Weise, D.; Miller, A.; Shrivastava, M.; Miller, J. W.; Mahalingam, S.; Princevac, M.; Jung, H.

    2010-08-01

    Particle size distribution from biomass combustion is an important parameter as it affects air quality, climate modelling and health effects. To date, particle size distributions reported from prior studies vary not only due to difference in fuels but also difference in experimental conditions. This study aims to report characteristics of particle size distributions in well controlled repeatable lab scale biomass fires for southwestern United States fuels with focus on chaparral. The combustion laboratory at the United States Department of Agriculture-Forest Service's Fire Science Laboratory (USDA-FSL), Missoula, MT provided a repeatable combustion and dilution environment ideal for measurements. For a variety of fuels tested the major mode of particle size distribution was in the range of 29 to 52 nm, which is attributable to dilution of the fresh smoke. Comparing mass size distribution from FMPS and APS measurement 51-68% of particle mass was attributable to the particles ranging from 0.5 to 10 μm for PM10. Geometric mean diameter rapidly increased during flaming and gradually decreased during mixed and smoldering phase combustion. Most fuels produced a unimodal distribution during flaming phase and strong biomodal distribution during smoldering phase. The mode of combustion (flaming, mixed and smoldering) could be better distinguished using the slopes in MCE (Modified Combustion Efficiency) vs. geometric mean diameter than only using MCE values.

  11. Particle size distributions from laboratory-scale biomass fires using fast response instruments

    NASA Astrophysics Data System (ADS)

    Hosseini, S.; Qi, L.; Cocker, D.; Weise, D.; Miller, A.; Shrivastava, M.; Miller, W.; Mahalingam, S.; Princevac, M.; Jung, H.

    2010-04-01

    Particle size distribution from biomass combustion is an important parameter as it affects air quality, climate modelling and health effects. To date particle size distributions reported from prior studies vary not only due to difference in fuels but also difference in experimental conditions. This study aims to report characteristics of particle size distribution in a well controlled repeatable lab scale biomass fires for southwestern US fuels. The combustion facility at the USDA Forest Service's Fire Science Laboratory (FSL), Missoula, MT provided repeatable combustion and dilution environment ideal for particle size distribution study. For a variety of fuels tested the major mode of particle size distribution was in the range of 29 to 52 nm, which was attributable to dilution of the fresh smoke. Comparing volume size distribution from Fast Mobility Particle Sizer (FMPS) and Aerodynamic Particle Sizer (APS) measurements, ~30% of particle volume was attributable to the particles ranging from 0.5 to 10 μm for PM10. Geometric mean diameter rapidly increased during flaming and gradually decreased during mixed and smoldering phase combustion. Most of fuels gave unimodal distribution during flaming phase and strong biomodal distribution during smoldering phase. The mode of combustion (flaming, mixed and smoldering) could be better distinguished using slopes in Modified Combustion Efficiency (MCE) vs. geometric mean diameter from each mode of combustion than only using MCE values.

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

    NASA Astrophysics Data System (ADS)

    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

  13. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    SciTech Connect

    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.

  14. Fungal spores are transported long distances in smoke from biomass fires

    NASA Astrophysics Data System (ADS)

    Mims, Sarah A.; Mims, Forrest M.

    Viable fungal spores are present in smoke from distant biomass fires. This finding has potentially important implications for prescribed burning, agricultural management and public health. While attempting to find fungal spores in dust blown from China to Texas, one of us (S.A.M.) discovered that smoke from Yucatan contains viable bacteria and fungal spores, including the genera Alternaria, Cladosporium, Fusariella and Curvularia. There was a high correlation ( r2=0.78) of spores and coarse carbon particles collected on microscope slides during 13 days of the 2002 smoke season. To eliminate possible contamination by local spores, an air sampler was flown from a kite at a Texas Gulf Coast beach during and after the 2003 smoke season on days when the NOAA back trajectory showed air arriving from Yucatan. Fifty-two spores and 19 coarse black carbon particles (>2.5 μm) were collected during a 30-min kite flight on the smoke day and 12 spores and four carbons on the day without smoke. We have found spores in smoke from an Arizona forest fire and in Asian smoke at Mauna Loa Observatory, Hawaii. We have tested these findings by burning dried grass, leaves, twigs and flood detritus. The smoke from all test fires contained many spores.

  15. Quantifying Post-Fire Forest Biomass Recovery in Northeastern Siberia using Hierarchical Multi-Sensor Satellite Imagery and Field Measurements

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Russian forests are the largest vegetation carbon pool outside of the tropics, with larch dominating northeastern Siberia where extreme temperatures, permafrost and wildfire currently limit persistence of other tree species. These ecosystems have experienced rapid climate warming over the past century and model simulations suggest that they will undergo profound changes by the end of the century if warming continues. Understanding the responses of these unique deciduous-conifer ecosystems to current and future climate is important given the potential changes in disturbance regimes and other climate feedbacks. The climate implications of changes in fire severity and return interval, as predicted under a warmer and drier climate, are not well understood given the trade-off between storage of C in forest biomass and post-fire surface albedo. We examined forest biomass recovery across a burn chronosequence near Cherskii, Sakha Republic, in far northeastern Siberia. We used high-quality Landsat imagery to date and map fires that occurred between 1972 and 2009, then complemented this data set using tree ring measurements to map older fires. A three stage approach was taken to map current biomass distribution. First, tree shadows were mapped from 50 cm panchromatic WorldView 1 imagery covering a portion of the region. Secondly, the tree shadow map was aggregated to 30 m resolution and used to train a regression-tree model that ingested mosaiced Landsat data. The model output correlated with allometry-based field estimates of biomass, allowing us to transform the model output to a map of regional aboveground biomass using a regression model. When combined with the fire history data, the new biomass map revealed a chronosequence of forest regrowth and carbon sequestration in aboveground biomass after fire. We discuss the potential for future carbon emissions from fires in northeastern Siberia, as well as carbon sequestration during recovery based on the observed biomass

  16. Thermal Spray Coatings for High-Temperature Corrosion Protection in Biomass Co-Fired Boilers

    NASA Astrophysics Data System (ADS)

    Oksa, M.; Metsäjoki, J.; Kärki, J.

    2015-01-01

    There are over 1000 biomass boilers and about 500 plants using waste as fuel in Europe, and the numbers are increasing. Many of them encounter serious problems with high-temperature corrosion due to detrimental elements such as chlorides, alkali metals, and heavy metals. By HVOF spraying, it is possible to produce very dense and well-adhered coatings, which can be applied for corrosion protection of heat exchanger surfaces in biomass and waste-to-energy power plant boilers. Four HVOF coatings and one arc sprayed coating were exposed to actual biomass co-fired boiler conditions in superheater area with a probe measurement installation for 5900 h at 550 and 750 °C. The coating materials were Ni-Cr, IN625, Fe-Cr-W-Nb-Mo, and Ni-Cr-Ti. CJS and DJ Hybrid spray guns were used for HVOF spraying to compare the corrosion resistance of Ni-Cr coating structures. Reference materials were ferritic steel T92 and nickel super alloy A263. The circulating fluidized bed boiler burnt a mixture of wood, peat and coal. The coatings showed excellent corrosion resistance at 550 °C compared to the ferritic steel. At higher temperature, NiCr sprayed with CJS had the best corrosion resistance. IN625 was consumed almost completely during the exposure at 750 °C.

  17. Thermal Spray Coatings for High-Temperature Corrosion Protection in Biomass Co-Fired Boilers

    NASA Astrophysics Data System (ADS)

    Oksa, M.; Metsäjoki, J.; Kärki, J.

    2014-09-01

    There are over 1000 biomass boilers and about 500 plants using waste as fuel in Europe, and the numbers are increasing. Many of them encounter serious problems with high-temperature corrosion due to detrimental elements such as chlorides, alkali metals, and heavy metals. By HVOF spraying, it is possible to produce very dense and well-adhered coatings, which can be applied for corrosion protection of heat exchanger surfaces in biomass and waste-to-energy power plant boilers. Four HVOF coatings and one arc sprayed coating were exposed to actual biomass co-fired boiler conditions in superheater area with a probe measurement installation for 5900 h at 550 and 750 °C. The coating materials were Ni-Cr, IN625, Fe-Cr-W-Nb-Mo, and Ni-Cr-Ti. CJS and DJ Hybrid spray guns were used for HVOF spraying to compare the corrosion resistance of Ni-Cr coating structures. Reference materials were ferritic steel T92 and nickel super alloy A263. The circulating fluidized bed boiler burnt a mixture of wood, peat and coal. The coatings showed excellent corrosion resistance at 550 °C compared to the ferritic steel. At higher temperature, NiCr sprayed with CJS had the best corrosion resistance. IN625 was consumed almost completely during the exposure at 750 °C.

  18. Merging satellite measurements of fire radiative energy and burned area products to estimate biomass burning: A European case study

    NASA Astrophysics Data System (ADS)

    Bistinas, I.; Saldaña, G. L.; Oom, D.; Sá, A. C.; Silva, J. M.; Pereira, J.

    2013-05-01

    Biomass burning is a key element of the terrestrial carbon cycle that influences the global radiation budget through the biomass consumption and the subsequently release of aerosols and trace gases into the atmosphere having huge impacts on the global climate. Recently, global products of daily fire activity have recorded Fire Radiative Power (FRP), providing a quantitative assessment of fire intensity across the globe. Several studies showed that FRP is proportional to the fire's fuel consumption and smoke emission rates through integration of the FRP over time, deriving the Fire Radiative Energy (FRE), which can be assumed as the total energy released over a spatio-temporal unit and used to infer total emissions from biomass burning in various ecosystems, omitting fuel load and combustion completeness information that are characterized by significant uncertainties at continental and global scale, and at the same time simplifying the computation of spatially explicit fuel consumption estimates. This study integrates spatial and temporal analysis using FRP data from the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) for the year 2008 and burned area from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor (MCD64A1) for the same year focusing on Europe. An intercomparison assessment of the emission estimates with the Global Fire Data Emissions Database (GFED) followed, due to lack of FRE and combustion measurements in large scale for validation. We show that the fire-emitted energy approach can be used in continental scale reducing uncertainties in emission estimates which may lead to simplification of the fire parameterization in fire modelling, yet in more robust simulations.

  19. Estimating Biomass Burning Injection Heights using CALIOP, MODIS, and NASA Langley Trajectory Model: Focus on the Tripod Fire, Washington 2006

    NASA Astrophysics Data System (ADS)

    Choi, H. D.; Roller, C. M.; Soja, A. J.; Fairlie, T. D.

    2014-12-01

    Biomass burning emissions have the potential to alter numerous land and atmospheric processes, which has strong implications for air quality and feedbacks within the climate system. Plume injection height influences plume transport characteristics, such as directly injected into the free troposphere, resulting the long-range transport. We developed a new method to estimate biomass burning plume injection heights with Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) aerosol data, Moderate Resolution Imaging Spectroradiometer (MODIS) Fire Detection data, and the NASA Langley Trajectory model. We use CALIOP aerosol information to initialize aerosol-filled air parcels in the Trajectory model. Then, the trajectory model is run backwards until there is a coincidence between MODIS fire detections and smoke parcels. In this presentation, we focus on the Tripod fire, one of the largest fires in the lower 48 in recent US history for July-August 2006. We examine biomass burning injection heights of the Tripod fire and evaluate the modeled plume injection height with satellite derived observed plume height.

  20. Properties and evolution of biomass burning organic aerosol from Canadian boreal forest fires

    NASA Astrophysics Data System (ADS)

    Jolleys, M. D.; Coe, H.; McFiggans, G.; Taylor, J. W.; O'Shea, S. J.; Le Breton, M.; Bauguitte, S. J.-B.; Moller, S.; Di Carlo, P.; Aruffo, E.; Palmer, P. I.; Lee, J. D.; Percival, C. J.; Gallagher, M. W.

    2015-03-01

    Airborne measurements of biomass burning organic aerosol (BBOA) from boreal forest fires reveal highly contrasting properties for plumes of different ages. These measurements, performed using an Aerodyne Research Inc. compact time-of-flight aerosol mass spectrometer (C-ToF-AMS) during the BORTAS (quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment in the summer of 2011, have been used to derive normalised excess organic aerosol (OA) mass concentrations (ΔOA / ΔCO), with higher average ratios observed closer to source (0.190±0.010) than in the far-field (0.097±0.002). The difference in ΔOA / ΔCO between fresh and aged plumes is influenced by a change in dominant combustion conditions throughout the campaign. Measurements at source comprised 3 plume interceptions during a single research flight and sampled largely smouldering fires. Twenty-three interceptions were made across four flights in the far-field, with plumes originating from fires occurring earlier in the campaign when fire activity had been more intense, creating an underlying contrast in emissions prior to any transformations associated with aging. Changing combustion conditions also affect the vertical distribution of biomass burning emissions, as aged plumes from more flaming-dominated fires are injected to higher altitudes of up to 6000 m. Proportional contributions of the mass-to-charge ratio (m/z) 60 and 44 peaks in the AMS mass spectra to the total OA mass (denoted f60 and f44) are used as tracers for primary and oxidised BBOA, respectively. f44 is lower on average in near-field plumes than those sampled in the far-field, in accordance with longer aging times as plumes are transported a greater distance from source. However, high levels of ΔO3 / ΔCO and -log(NOx / NOy) close to source indicate that emissions can be subject to very rapid oxidation over short timescales. Conversely, the lofting of plumes into the

  1. 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

    NASA Astrophysics Data System (ADS)

    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.

  2. Oxidation of ketone groups in transported biomass burning aerosol from the 2008 Northern California Lightning Series fires

    NASA Astrophysics Data System (ADS)

    Hawkins, Lelia N.; Russell, Lynn M.

    2010-11-01

    Submicron particles were collected from June to September 2008 in La Jolla, California to investigate the composition and sources of atmospheric aerosol in an anthropogenically-influenced coastal site. Factor analysis of aerosol mass spectrometry (AMS) and Fourier transform infrared (FTIR) spectroscopy measurements revealed that the two largest sources of submicron organic mass (OM) at the sampling site were (1) fossil fuel combustion associated with ship and diesel truck emissions near the ports of Los Angeles and Long Beach and (2) aged smoke from large wildfires burning in central and northern California. During non-fire periods, fossil fuel combustion contributed up to 95% of FTIR OM, correlated to sulfur, and consisted mostly of alkane (86%) and carboxylic acid groups (9%). During fire periods, biomass burning contributed up to 74% of FTIR OM, consisted mostly of alkane (48%), ketone (25%), and carboxylic acid groups (17%), and correlated to AMS-derived factors resembling brush fire smoke, wood smoldering and flaming particles, and biogenic secondary organic aerosol. The two AMS-derived biomass burning factors were identified as oxygenated and hydrocarbon biomass burning aerosol on the basis of spectral similarities to smoldering and flaming smoke particles, respectively. In addition, the ratio of oxygenated to hydrocarbon biomass burning OM shows a clear diurnal trend with an afternoon peak, consistent with photochemical oxidation. Back trajectory analysis indicates that 2-4-day old forest fire emissions include substantial ketone groups, which have both lower O/C and lower m/ z 44/OM fraction than carboxylic acid groups. Air masses with more than 4-day old emissions have higher carboxylic acid/ketone group ratios, showing that atmospheric processing of these ketone-containing organic aerosol particles results in increased m/ z 44 and O/C. These observations may provide functionally-specific evidence for the type of chemical processing that is responsible for

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

    SciTech Connect

    Jenkins, Bryan M.; Williams, Robert B.; Turn, Scott Q.; Jakeway, Lee A.; 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

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

    NASA Astrophysics Data System (ADS)

    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

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

    USGS Publications Warehouse

    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. The 1985 Biomass Burning Season in South America: Satellite Remote Sensing of Fires, Smoke, and Regional Radiative Energy Budgets

    NASA Technical Reports Server (NTRS)

    Christopher, Sundar A.; Wang, Min; Berendes, Todd A.; Welch, Ronald M.; Yang, Shi-Keng

    1998-01-01

    Using satellite imagery, more than five million square kilometers of the forest and cerrado regions over South America are extensively studied to monitor fires and smoke during the 1985 biomass burning season. The results are characterized for four major ecosystems, namely: (1) tropical rain forest, (2) tropical broadleaf seasonal, (3) savannah/grass and seasonal woods (SGW), and (4) mild/warm/hot grass/shrub (MGS). The spatial and temporal distribution of fires are examined from two different methods using the multispectral Advanced Very High Resolution Radiometer Local Area Coverage data. Using collocated measurements from the instantaneous scanner Earth Radiation Budget Experiment data, the direct regional radiative forcing of biomass burning aerosols is computed. The results show that more than 70% of the fires occur in the MGS and SGW ecosystems due to agricultural practices. The smoke generated from biomass burning has negative instantaneous net radiative forcing values for all four major ecosystems within South America. The smoke found directly over the fires has mean net radiative forcing values ranging from -25.6 to -33.9 W m(exp -2). These results confirm that the regional net radiative impact of biomass burning is one of cooling. The spectral and broadband properties for clear-sky and smoke regions are also presented that could be used as input and/or validation for other studies attempting to model the impact of aerosols on the earth-atmosphere system. These results have important applications for future instruments from the Earth Observing System (EOS) program. Specifically, the combination of the Visible Infrared Scanner and Clouds and the Earth's Radiant Energy System (CERES) instruments from the Tropical Rainfall Measuring Mission and the combination of Moderate Resolution Imaging Spectrometer and CERES instruments from the EOS morning crossing mission could provide reliable estimates of the direct radiative forcing of aerosols on a global scale

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

    SciTech Connect

    Baxter, L.L.; Miles, T.R.; Miles, T.R. Jr.; Jenkins, B.M.; Dayton, D.C.; Milne, T.A.; Bryers, R.W.; Oden, L.L.

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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

  11. Fly ash and concrete: a study determines whether biomass, or coal co-firing fly ash, can be used in concrete

    SciTech Connect

    Wang, Shuangzhen; Baxter, Larry

    2006-08-01

    Current US national standards for using fly ash in concrete (ASTM C618) state that fly ash must come from coal combustion, thus precluding biomass-coal co-firing fly ash. The co-fired ash comes from a large and increasing fraction of US power plants due to rapid increases in co-firing opportunity fuels with coal. The fly ashes include coal fly ash, wood fly ash from pure wood combustion, biomass and coal co-fired fly ash SW1 and SW2. Also wood fly ash is blended with Class C or Class F to produce Wood C and Wood E. Concrete samples were prepared with fly ash replacing cement by 25%. All fly ash mixes except wood have a lower water demand than the pure cement mix. Fly ashes, either from coal or non coal combustion, increase the required air entraining agent (AEA) to meet the design specification of the mixes. If AEA is added arbitrarily without considering the amount or existence of fly ash results could lead to air content in concrete that is either too low or too high. Biomass fly ash does not impact concrete setting behaviour disproportionately. Switch grass-coal co-fired fly ash and blended wood fly ash generally lie within the range of pure coal fly ash strength. The 56 day flexure strength of all the fly ash mixes is comparable to that of the pure cement mix. The flexure strength from the coal-biomass co-fired fly ash does not differ much from pure coal fly ash. All fly ash concrete mixes exhibit lower chloride permeability than the pure cement mixes. In conclusion biomass coal co-fired fly ash perform similarly to coal fly ash in fresh and hardened concrete. As a result, there is no reason to exclude biomass-coal co-fired fly ash in concrete.

  12. Evaluating Post-fire Ecosystem Effects in Tussock Tundra of the Seward Peninsula: Characterizing Above-ground Biomass Accumulation, Soil Nutrient Pools, and Foliar Nitrogen.

    NASA Astrophysics Data System (ADS)

    Hollingsworth, T. N.; Mack, M. C.; Breen, A. L.

    2014-12-01

    Over the last century in the circumpolar north, changes in vegetation include shrub cover expansion and shifts in tree line. Invasion of tundra by trees and shrubs may be further facilitated by wildfire disturbance, which creates opportunities for establishment where recruitment is otherwise rare. Even moderate increases in warm-season temperatures are predicted to increase the likelihood of tundra fires. Understanding the consequences of a change in fire regime are complicated by the fact that there are relatively few large recent fires to study. However, the Seward Peninsula is a region that currently experiences more frequent and large fires than other tundra regions in Arctic Alaska. In this tundra region, there are areas of overlapping burns dating back to the 1970s. Using a chronosequence approach, we looked at post-fire biomass accumulation as well as foliar and soil C and N. Our experimental design incorporated sites that showed no evidence of recent burning, sites that burned in 1971, 1997, 2002, and 2011 as well as sites that burned multiple times over the last 30 years. We found that fire had a significant effect on total biomass and shrub basal area in tussock tundra. Our site that burned in 2011 had the lowest total biomass, about half of the biomass of our unburned site. However, our results indicated the site that burned in 1971 had over double the aboveground biomass and more soil N than the unburned site. We found that sites that repeatedly burned since 1971 were very similar in biomass to unburned tundra. This suggests that repeat fires keep a post-fire site at unburned levels of biomass. However, in these repeat fire sites, foliar C/N was ~25% greater and soil C and N was ~50% less than in unburned tundra. These results indicate that repeat fires are potentially causing nitrogen loss that not likely to be replenished into the system. As tundra fires become more frequent prediction of post-fire ecosystem effects is critical due to impacts on

  13. EPICA Dome C ice core fire record demonstrates a major biomass burning increase over the past 500 years

    NASA Astrophysics Data System (ADS)

    Kehrwald, Natalie; Power, Mitchell; Zennaro, Piero; McWethy, David; Whitlock, Cathy; Zangrando, Roberta; Gambaro, Andrea; Barbante, Carlo

    2013-04-01

    Natural factors and human activity influence fire variability including changes in temperature and precipitation, increasing greenhouse gas concentrations, altering ignitions, vegetation cover and fuel availability. Ice cores archive chemical signatures of both past climate and fire activity, and understanding this interaction is increasingly important in a warming climate. The specific molecular marker levoglucosan (1,6-anhydro-ß-D-glucopyranose) can only be produced by burning woody tissue at temperatures greater than 300°C. Levoglucosan is present in the fine fraction of smoke plumes, is transported distances of thousands of kilometers, is deposited on glacier surfaces, and is detectable in both polar and mountain ice cores providing an unambiguous fire history. Here, we present a high-resolution 10,000-year levoglucosan record in the EPICA Dome C (75°06'S, 123°21'E, 3233 masl) ice core and implications for determining natural and human-caused fire variability. A recent provocative hypothesis by Ruddiman suggests that humans may have had a significant impact on the Earth's climate thousands of years ago through carbon and methane emissions originating from biomass burning associated with early agriculture. This hypothesis is centered on the observation that atmospheric carbon dioxide and methane levels recorded in ice cores increased irrespective of insolation changes beginning 7,000 to 5,000 years before present. The EDC levoglucosan record does not demonstrate augmented fire activity at 5000 and/or 7000 years ago in the Southern Hemisphere. We are currently determining Holocene levoglucosan concentrations in the NEEM, Greenland (77°27' N; 51°3'W, 2454 masl) ice core to provide a Northern Hemisphere comparison at 5000 and/or 7000 years ago. The highest EDC Holocene fire activity occurs during the past 500 years. Mean levoglucosan concentrations between 500 to 10,000 BP are approximately 50 ppt, but rise to 300 ppt at present. This substantial increase is

  14. Fires

    MedlinePlus

    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 ...

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Ammonia emissions in tropical biomass burning regions: Comparison between satellite-derived emissions and bottom-up fire inventories

    NASA Astrophysics Data System (ADS)

    Whitburn, S.; Van Damme, M.; Kaiser, J. W.; van der Werf, G. R.; Turquety, S.; Hurtmans, D.; Clarisse, L.; Clerbaux, C.; Coheur, P.-F.

    2015-11-01

    Vegetation fires emit large amounts of nitrogen compounds in the atmosphere, including ammonia (NH3). These emissions are still subject to large uncertainties. In this study, we analyze time series of monthly NH3 total columns (molec cm-2) from the IASI sounder on board MetOp-A satellite and their relation with MODIS fire radiative power (MW) measurements. We derive monthly NH3 emissions estimates for four regions accounting for a major part of the total area affected by fires (two in Africa, one in central South America and one in Southeast Asia), using a simplified box model, and we compare them to the emissions from both the GFEDv3.1 and GFASv1.0 biomass burning emission inventories. In order to strengthen the analysis, we perform a similar comparison for carbon monoxide (CO), also measured by IASI and for which the emission factors used in the inventories to convert biomass burned to trace gas emissions are thought to be more reliable. In general, a good correspondence between NH3 and CO columns and the FRP is found, especially for regions in central South America with correlation coefficients of 0.82 and 0.66, respectively. The comparison with the two biomass burning emission inventories GFASv1.0 and GFEDv3.1 shows good agreements, particularly in the time of the maximum of emissions for the central South America region and in the magnitude for the region of Africa south of the equator. We find evidence of significant non-pyrogenic emissions for the regions of Africa north of the equator (for NH3) and Southeast Asia (for NH3 and CO). On a yearly basis, total emissions calculated from IASI measurements for the four regions reproduce fairly well the interannual variability from the GFEDv3.1 and GFASv1.0 emissions inventories for NH3 but show values about 1.5-2 times higher than emissions given by the two biomass burning emission inventories, even when assuming a fairly long lifetime of 36 h for that species.

  18. Fire, defoliation, and competing species alter Aristida purpurea biomass, tiller, and axillary bud production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aristida purpurea (threeawn) is a competitive native perennial grass with monoculturistic tendencies and poor palatability. We examined effects of fire, defoliation, and interspecific/intraspecific planting for 1) threeawn responses in the presence of threeawn, Bouteloua gracilis, or Pascopyrum smi...

  19. ENVIRONMENTAL AND SUSTAINABLE TECHNOLOGY EVALUATION: BIOMASS CO-FIRING IN INDUSTRIAL BOILERS--UNIVERSITY OF IOWA

    EPA Science Inventory

    The U.S. EPA operates the Environmental and Sustainable Technology Evaluation (ESTE) program to facilitate the deployment of innovative technologies through performance verification and information dissemination. This ESTE project involved evaluation of co-firing common woody bio...

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

    PubMed Central

    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. PMID:26379249

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

    PubMed

    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. PMID:26379249

  2. Design and operation of a solar fired biomass flash pyrolysis reactor

    SciTech Connect

    Antal, M.J.; Hofmann, L.; Brown, C.T.; Steenblick, R.

    1981-01-01

    The results of continuing research on the radiant flash pyrolysis of biomass as a source of fluid fuels, industrial feedstocks, and chemicals are described. Bench-scale sources of intense, visible radiant energy were used to simulate the concentrated solar flux available at the focus of solar towers. Windowed transport reactors were developed, which act as cavity receivers for the focused radiant energy and provide a means for direct use of the radiation to rapidly pyrolyze the entering biomass. Detailed result of both bench scale experiments and experiments using the Georgia Tech 400 kW (thermal) solar furnace are presented. These results suggest the use of concentrated radiant energy as a selective means for the production of either a hydrocarbon-rich synthesis gas or sugar related syrups from biomass by flash pyrolysis. Sawdust, ground corncobs, and powdered microcrystal cellulose were the biomass feedstocks in this work.

  3. Experimental evaluation of a solar fired flash pyrolysis of biomass reactor

    SciTech Connect

    Antal, M.J. Jr.; Edwards, W.E.; Steenblik, R.A.; Brown, C.T.; Knight, J.A.; Elston, L.W.; Hurst, D.R.

    1981-01-01

    A Princeton-Georgia Institute of Technology flash pyrolysis of biomass test program was conducted at the DOE Advanced Components Test Facility (CTF) at Georgia Tech in August 1980. The 400 kWth solar thermal facility was used to provide a source of highly concentrated radiant energy for the flash pyrolysis of four types of biomass in a steam counterflow quartz reactor. The biomass materials were microcrystalline cellulose, hardwood sawdust, ground corn cob, and Kraft lignin. The experiments at Princeton and Georgia Tech suggest the use of concentrated radiant energy as a selective means for the production of either a hydrocarbon rich synthesis gas or sugar related syrups from biomass by flash pyrolysis. Experiments at Princeton have indicated that sugar related syrups are selectively produced when the biomass particles are rapidly heated by radiation in a cool gaseous environment. The gas temperatures in the reactor during the test program at Georgia Tech were relatively high, which selectively turned the chemistry toward the production of hydrocarbon rich synthesis gases.

  4. Open-path Fourier transform infrared studies of large-scale laboratory biomass fires

    NASA Astrophysics Data System (ADS)

    Yokelson, Robert J.; Griffith, David W. T.; Ward, Darold E.

    1996-09-01

    A series of nine large-scale, open fires was conducted in the Intermountain Fire Sciences Laboratory (IFSL) controlled-environment combustion facility. The fuels were pure pine needles or sagebrush or mixed fuels simulating forest-floor, ground fires; crown fires; broadcast burns; and slash pile burns. Mid-infrared spectra of the smoke were recorded throughout each fire by open path Fourier transform infrared (FTIR) spectroscopy at 0.12 cm-1 resolution over a 3 m cross-stack pathlength and analyzed to provide pseudocontinuous, simultaneous concentrations of up to 16 compounds. Simultaneous measurements were made of fuel mass loss, stack gas temperature, and total mass flow up the stack. The products detected are classified by the type of process that dominates in producing them. Carbon dioxide is the dominant emission of (and primarily produced by) flaming combustion, from which we also measure nitric oxide, nitrogen dioxide, sulfur dioxide, and most of the water vapor from combustion and fuel moisture. Carbon monoxide is the dominant emission formed primarily by smoldering combustion from which we also measure carbon dioxide, methane, ammonia, and ethane. A significant fraction of the total emissions is unoxidized pyrolysis products; examples are methanol, formaldehyde, acetic and formic acid, ethene (ethylene), ethyne (acetylene), and hydrogen cyanide. Relatively few previous data exist for many of these compounds and they are likely to have an important but as yet poorly understood role in plume chemistry. Large differences in emissions occur from different fire and fuel types, and the observed temporal behavior of the emissions is found to depend strongly on the fuel bed and product type.

  5. Chemical and physical properties of cyclone fly ash from the grate-fired boiler incinerating forest residues at a small municipal district heating plant (6MW).

    PubMed

    Pöykiö, R; Rönkkömäki, H; Nurmesniemi, H; Perämäki, P; Popov, K; Välimäki, I; Tuomi, T

    2009-03-15

    In Finland, the new limit values for maximal allowable heavy metal concentrations for materials used as an earth construction agent came into force in July 2006. These limit values are applied if ash is utilized, e.g. in roads, cycling paths, pavements, car parks, sport fields, etc. In this study we have determined the most important chemical and physical properties of the cyclone fly ash originating from the grate-fired boiler incinerating forest residues (i.e. wood chips, sawdust and bark) at a small municipal district heating plant (6 MW), Northern Finland. This study clearly shows that elements are enriched in cyclone fly ash, since the total element concentrations in the cyclone fly ash were within 0.2-10 times higher than those in the bottom ash. The total concentrations of Cd (25 mg kg(-1); d.w.), Zn (3630 mg kg(-1); d.w.), Ba (4260 mg kg(-1); d.w.) and Hg (1.7 mg kg(-1); d.w.) exceeded the limit values, and therefore the cyclone fly ash cannot be used as an earth construction agent. According to the leached amounts of Cr (38 mg kg(-1); d.w.), Zn (51 mg kg(-1); d.w.) and sulphate (50,000 mg kg(-1); d.w.), the cyclone fly ash is classified as a hazardous waste, and it has to be deposited in a hazardous waste landfill. PMID:18603362

  6. On the use of fire radiative power, area, and temperature estimates to characterize biomass burning via moderate to coarse spatial resolution remote sensing data in the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Schroeder, Wilfrid; Csiszar, Ivan; Giglio, Louis; Schmidt, Christopher C.

    2010-11-01

    Spaceborne instruments provide a unique view of global vegetation fire activity many times a day. In this study, we assessed the fire characterization information provided by two major products: the Terra and Aqua MODIS Thermal Anomalies product (MOD14 and MYD14, respectively) and the Wildfire Automated Biomass Burning Algorithm (WF_ABBA) product derived from GOES East Imager. Using higher spatial resolution imagery data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Landsat Enhanced Thematic Mapper Plus (ETM+) instruments, we analyzed the characterization of subpixel fires detected by MOD14, MYD14, and WF_ABBA over parts of Brazilian Amazonia. Our results suggest that MODIS and GOES fire radiative power (FRP) estimates derived for individual fire-pixel clusters are subject to errors due to the effects of the point spread function of those instruments (underestimation of up to 75%), improper fire background characterization (overestimation of up to 80% assuming a 10 K cold bias in background temperature), and omission of small fire lines. Detection limits were approximately 11 and 9 MW for MOD14 and MYD14, respectively, and were equivalent to 27 and 19 MW for WF_ABBA data acquired coincidently with MOD14 and MYD14, respectively. We found a positive correlation between FRP and percentage tree cover indicating that FRP is sensitive to biomass density. Fire area and temperature estimates derived from the application of Dozier's (1981) approach to GOES data did not agree with our reference data (i.e., ASTER and ETM+ active fire masks and in situ fire temperature data), suggesting that large and variable errors could affect the retrieval of those parameters.

  7. Influence of Prescribed Fire on Ecosystem Biomass, Carbon, and Nitrogen in a Pinyon Juniper Woodland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pinyon and juniper woodland encroachment associated with climate change and land use history in the Great Basin is thought to provide offsets for carbon emissions. However, the largest pools of carbon in arid landscapes are typically found in soils, and aboveground biomass cannot be considered long ...

  8. Evaluation of Biomass Gasification to Produce Reburning Fuel for Coal-Fired Boilers

    EPA Science Inventory

    Gasification and reburning testing with biomass and other wastes is of interest to both the U.S. EPA and the Italian Ministry of the Environment & Territory. Gasification systems that use biofuels or wastes as feedstock can provide a clean, efficient source of synthesis gas and p...

  9. Biomass uptake and fire as controls on groundwater solute evolution on a southeast Australian granite: aboriginal land management hypothesis

    NASA Astrophysics Data System (ADS)

    Dean, J. F.; Webb, J. A.; Jacobsen, G. E.; Chisari, R.; Dresel, P. E.

    2014-08-01

    The chemical composition of groundwater and surface water is often considered to be dominated by water-rock interactions, particularly weathering; however, it has been increasingly realised that plant uptake can deplete groundwater and surface water of nutrient elements. Here we show, using geochemical mass balance techniques, that water-rock interactions do not control the hydrochemistry at our study site within a granite terrain in southwest Victoria, Australia. Instead the chemical species provided by rainfall are depleted by plant biomass uptake and exported, predominantly through fire. Regular landscape burning by Aboriginal land users is hypothesized to have caused the depletion of chemical species in groundwater for at least the past 20 000 yr by accelerating the export of elements that would otherwise have been stored within the local biomass. These findings are likely to be applicable to silicate terrains throughout southeast Australia, as well as similar lithological and climatic regions elsewhere in the globe, and contrast with studies of groundwater and surface water chemistry in higher rainfall areas of the Northern Hemisphere, where water-rock interactions are the dominant hydrochemical control.

  10. Biomass uptake and fire as controls on groundwater solute evolution on a southeast Australian granite: aboriginal land management hypothesis

    NASA Astrophysics Data System (ADS)

    Dean, J. F.; Webb, J. A.; Jacobsen, G.; Chisari, R.; Dresel, P. E.

    2014-01-01

    The chemical composition of groundwater and surface water is often considered to be dominated by water-rock interactions, particularly weathering; however, it has been increasingly realised that plant uptake can deplete groundwater and surface water of nutrient elements. Here we show, using geochemical mass balance techniques that at our study site in Southwest Victoria, Australia, water-rock interactions do not control the hydrochemistry. Instead the chemical species provided by rainfall are depleted by plant biomass uptake and exported, predominantly through fire. Regular landscape burning by Aboriginal land users is hypothesized to have caused the depletion of chemical species in groundwater for at least the past 20 000 yr by accelerating the export of elements that would otherwise have been stored within the local biomass. These findings are likely to be representative of southeast Australia, as well as similar climatic regions elsewhere in the globe, and contrast with Northern Hemisphere studies of groundwater and surface water chemistry, where water-rock interactions are the dominant hydrochemical control.

  11. Combustion, pyrolysis, gasification, and liquefaction of biomass

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  13. Emissions of SO2, NO and N2O in a circulating fluidized bed combustor during co-firing coal and biomass.

    PubMed

    Xie, Jian-jun; Yang, Xue-min; Zhang, Lei; Ding, Tong-li; Song, Wen-li; Lin, Wei-gang

    2007-01-01

    This paper presents the experimental investigations of the emissions of SO2, NO and N20 in a bench scale circulating fluidized bed combustor for coal combustion and co-firing coal and biomass. The thermal capacity of the combustor is 30 kW. The setup is electrically heated during startup. The influence of the excess air, the degree of the air staging, the biomass share and the feeding position of the fuels on the emissions of SO2, NO and N2O were studied. The results showed that an increase in the biomass shares resulted in an increase of the CO concentration in the flue gas, probably due to the high volatile content of the biomass. In co-firing, the emission of SO2 increased with increasing biomass share slightly, however, non-linear increase relationship between SO2 emission and fuel sulfur content was observed. Air staging significantly decreased the NO emission without raising the SO2 level. Although the change of the fuel feeding position from riser to downer resulted in a decrease in the NO emission level, no obvious change was observed for the SO2 level. Taking the coal feeding position R as a reference, the relative NO emission could significantly decrease during co-firing coal and biomass when feeding fuel at position D and keeping the first stage stoichiometry greater than 0.95. The possible mechanisms of the sulfur and nitrogen chemistry at these conditions were discussed and the ways of simultaneous reduction of SO2, NO and N20 were proposed. PMID:17913163

  14. Impact of blend ratio on the co-firing of a commercial torrefied biomass and coal via analysis of oxidation kinetics.

    PubMed

    Goldfarb, Jillian L; Liu, Chao

    2013-12-01

    Incorporation of torrefied biomass into coal-fired power plants could potentially lower the SOx and net CO2 emissions resulting from electricity generation. However, concerns over lower heating values and slightly higher ash content of torrefied biomass suggest that blending it with coal in industrial boilers may be preferable to complete fuel transition. By studying the oxidation kinetics of coal-torrefied biomass blends in a thermogravimetric analyzer at a heating rate of 100°C/min, we find an additive nature among the fuels for peak mass loss rates and enthalpies of combustion. The activation energy required to initiate decomposition decreases from 132.6 to 77.6 kJ/mol as the torrefied biomass increases from 0 to 100 wt%, with a sharp decrease between 0 and 40 wt%. Data suggest that incorporation of torrefied biomass into coal-fired boilers is dependent on the ability to sacrifice heating value for the lower emissions of SOx and net CO2 garnered using bio-coal. PMID:24113546

  15. Fireside Corrosion Behavior of HVOF and Plasma-Sprayed Coatings in Advanced Coal/Biomass Co-Fired Power Plants

    NASA Astrophysics Data System (ADS)

    Hussain, T.; Dudziak, T.; Simms, N. J.; Nicholls, J. R.

    2013-06-01

    This article presents a systematic evaluation of coatings for advanced fossil fuel plants and addresses fireside corrosion in coal/biomass-derived flue gases. A selection of four candidate coatings: alloy 625, NiCr, FeCrAl and NiCrAlY were deposited onto superheaters/reheaters alloy (T91) using high-velocity oxy-fuel (HVOF) and plasma spraying. A series of laboratory-based fireside corrosion exposures were carried out on these coated samples in furnaces under controlled atmosphere for 1000 h at 650 °C. The tests were carried out using the "deposit-recoat" test method to simulate the environment that was anticipated from air-firing 20 wt.% cereal co-product mixed with a UK coal. The exposures were carried out using a deposit containing Na2SO4, K2SO4, and Fe2O3 to produce alkali-iron tri-sulfates, which had been identified as the principal cause of fireside corrosion on superheaters/reheaters in pulverized coal-fired power plants. The exposed samples were examined in an ESEM with EDX analysis to characterize the damage. Pre- and post-exposure dimensional metrologies were used to quantify the metal damage in terms of metal loss distributions. The thermally sprayed coatings suffered significant corrosion attack from a combination of aggressive combustion gases and deposit mixtures. In this study, all the four plasma-sprayed coatings studied performed better than the HVOF-sprayed coatings because of a lower level of porosity. NiCr was found to be the best performing coating material with a median metal loss of ~87 μm (HVOF sprayed) and ~13 μm (plasma sprayed). In general, the median metal damage for coatings had the following ranking (in the descending order: most to the least damage): NiCrAlY > alloy 625 > FeCrAl > NiCr.

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

    SciTech Connect

    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.

  17. First Characterization of Biomass Burning Smoke from Cooking Fires, Peat, Crop Residue and Other Fuels By High Resolution PTR-TOF Mass Spectrometry and FTIR

    NASA Astrophysics Data System (ADS)

    Stockwell, C.; Veres, P. R.; Williams, J.; Yokelson, R. J.

    2014-12-01

    Biomass burning (BB) is a major influence on Earth's atmosphere, but for many fire-types the emissions have only been measured for a few species. For all types of BB, progress has been limited by a lack of information on the emissions of semi-volatile organic gases that are precursors for secondary aerosol and ozone. During the Fourth Fire Lab at Missoula Experiment (FLAME-4), the BB emissions from 158 laboratory fires were quantified by ~40 scientists for an assortment of globally relevant fuels including rarely sampled sources such as US and Asian crop residue; Indonesian and extratropical peat; and cooking fires in traditional and advanced stoves. In this work, we present the primary emissions of gas-phase non-methane organic compounds (NMOCs) measured using an advanced Proton-Transfer-Reaction time-of-flight mass spectrometer (PTR-TOF-MS) in tandem with measurements of other major emissions by Fourier transform infrared (FTIR) spectroscopy. We developed a composition and mass dependent sensitivity and best assignments for many observed peaks. The known and tentatively assigned peaks together account for ~80-96% of total observed NMOC mass. Much of the NMOC mass is rarely measured or previously unmeasured high molecular mass compounds including ringed aromatic hydrocarbons, phenolic compounds, and furans, which are all secondary organic aerosol precursors. Large air quality benefits are demonstrated for more advanced cooking technologies. This work produced globally relevant emission ratios and emission factors to better represent biomass burning in current atmospheric models.

  18. Grassland and forest understory biomass emissions from prescribed fires in the southeastern United States – RxCADRE 2012

    EPA Science Inventory

    Smoke measurements were made during grass and forest understory prescribed fires as part of a comprehensive program to understand fire and smoke behaviour. Instruments deployed on the ground, airplane and tethered aerostat platforms characterized the smoke plumes through measure...

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

    NASA Astrophysics Data System (ADS)

    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

  20. Grating lobes

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The radiation patterns characteristic of an indefinite planar array of isotropic antennas was investigated. Particular emphasis was given to the grating lobe scatter from the rectenna. It is shown that an idealy arrayed rectenna of indefinite extent would produce grating lobes which are impulsive. It is further shown that a shift to finite extent or introduction of typical variations in element placement should generate more typical patterns.

  1. Characterization of biomass burning emissions from cooking fires, peat, crop residue, and other fuels with high-resolution proton-transfer-reaction time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Stockwell, C. E.; Veres, P. R.; Williams, J.; Yokelson, R. J.

    2015-01-01

    We deployed a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) to measure biomass-burning emissions from peat, crop residue, cooking fires, and many other fire types during the fourth Fire Lab at Missoula Experiment (FLAME-4) laboratory campaign. A combination of gas standard calibrations and composition sensitive, mass-dependent calibration curves was applied to quantify gas-phase non-methane organic compounds (NMOCs) observed in the complex mixture of fire emissions. We used several approaches to assign the best identities to most major "exact masses", including many high molecular mass species. Using these methods, approximately 80-96% of the total NMOC mass detected by the PTR-TOF-MS and Fourier transform infrared (FTIR) spectroscopy was positively or tentatively identified for major fuel types. We report data for many rarely measured or previously unmeasured emissions in several compound classes including aromatic hydrocarbons, phenolic compounds, and furans; many of these are suspected secondary organic aerosol precursors. A large set of new emission factors (EFs) for a range of globally significant biomass fuels is presented. Measurements show that oxygenated NMOCs accounted for the largest fraction of emissions of all compound classes. In a brief study of various traditional and advanced cooking methods, the EFs for these emissions groups were greatest for open three-stone cooking in comparison to their more advanced counterparts. Several little-studied nitrogen-containing organic compounds were detected from many fuel types, that together accounted for 0.1-8.7% of the fuel nitrogen, and some may play a role in new particle formation.

  2. Characterization of biomass burning smoke from cooking fires, peat, crop residue and other fuels with high resolution proton-transfer-reaction time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Stockwell, C. E.; Veres, P. R.; Williams, J.; Yokelson, R. J.

    2014-08-01

    We deployed a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) to measure biomass burning emissions from peat, crop-residue, cooking fires, and many other fire types during the fourth Fire Lab at Missoula Experiment (FLAME-4) laboratory campaign. A combination of gas standards calibrations and composition sensitive, mass dependent calibration curves were applied to quantify gas-phase non-methane organic compounds (NMOCs) observed in the complex mixture of fire emissions. We used several approaches to assign best identities to most major "exact masses" including many high molecular mass species. Using these methods approximately 80-96% of the total NMOC mass detected by PTR-TOF-MS and FTIR was positively or tentatively identified for major fuel types. We report data for many rarely measured or previously unmeasured emissions in several compound classes including aromatic hydrocarbons, phenolic compounds, and furans; many of which are suspected secondary organic aerosol precursors. A large set of new emission factors (EFs) for a range of globally significant biomass fuels is presented. Measurements show that oxygenated NMOCs accounted for the largest fraction of emissions of all compound classes. In a brief study of various traditional and advanced cooking methods, the EFs for these emissions groups were greatest for open 3-stone cooking in comparison to their more advanced counterparts. Several little-studied nitrogen-containing organic compounds were detected from many fuel types that together accounted for 0.1-8.7% of the fuel nitrogen and some may play a role in new particle formation.

  3. Integrated Active Fire Retrievals and Biomass Burning Emissions Using Complementary Near-Coincident Ground, Airborne and Spaceborne Sensor Data

    NASA Technical Reports Server (NTRS)

    Schroeder, Wilfrid; Ellicott, Evan; Ichoku, Charles; Ellison, Luke; Dickinson, Matthew B.; Ottmar, Roger D.; Clements, Craig; Hall, Dianne; Ambrosia, Vincent; Kremens, Robert

    2013-01-01

    Ground, airborne and spaceborne data were collected for a 450 ha prescribed fire implemented on 18 October 2011 at the Henry W. Coe State Park in California. The integration of various data elements allowed near coincident active fire retrievals to be estimated. The Autonomous Modular Sensor-Wildfire (AMS) airborne multispectral imaging system was used as a bridge between ground and spaceborne data sets providing high quality reference information to support satellite fire retrieval error analyses and fire emissions estimates. We found excellent agreement between peak fire radiant heat flux data (less than 1% error) derived from near-coincident ground radiometers and AMS. Both MODIS and GOES imager active fire products were negatively influenced by the presence of thick smoke, which was misclassified as cloud by their algorithms, leading to the omission of fire pixels beneath the smoke, and resulting in the underestimation of their retrieved fire radiative power (FRP) values for the burn plot, compared to the reference airborne data. Agreement between airborne and spaceborne FRP data improved significantly after correction for omission errors and atmospheric attenuation, resulting in as low as 5 difference between AquaMODIS and AMS. Use of in situ fuel and fire energy estimates in combination with a collection of AMS, MODIS, and GOES FRP retrievals provided a fuel consumption factor of 0.261 kg per MJ, total energy release of 14.5 x 10(exp 6) MJ, and total fuel consumption of 3.8 x 10(exp 6) kg. Fire emissions were calculated using two separate techniques, resulting in as low as 15 difference for various species

  4. Biomass Burning

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Cofer, Wesley R., III; Pinto, Joseph P.

    1993-01-01

    Biomass burning may be the overwhelming regional or continental-scale source of methane (CH4) as in tropical Africa and a significant global source of CH4. Our best estimate of present methane emissions from biomass burning is about 51.9 Tg/yr, or 10% of the annual methane emissions to the atmosphere. Increased frequency of fires that may result as the Earth warms up may result in increases in this source of atmospheric methane.

  5. Linking Horizontal And Vertical Transports of Biomass Fire Emissions to the Tropical Atlantic Ozone Paradox during the Northern Hemisphere Winter Season: II. 1998-1999.

    NASA Technical Reports Server (NTRS)

    Jenkins, Gregory S.; Ryu, Jung-Hee; Thompson, Anne M.; Witte, Jacquelyn C.

    2002-01-01

    The horizontal and vertical transport of biomass fire emissions in West Africa during November 1998 through February 1999, are examined using all available data including wind, fire, aerosol, precipitation, lightning and outgoing longwave radiation. Ozonesonde data from the Aerosols99 Trans-Atlantic cruise are also included with rain and wind analyses. The results here support earlier studies that ozone and ozone precursors associated with biomass burning are confined to the lower troposphere primarily due to the lack of deep convection over land areas. Ozone and its precursors are horizontally transported equatorward or towards the west by winds in the 1000-700 hPa layers. However, rising adiabatic motions associated with the diurnal evolution of the West African n can transport ozone and its precursors vertically into the free troposphere above the marine boundary layer. Moreover, lightning from South America, Central Africa and mesoscale convective systems in the Gulf of Guinea can lead to elevated ozone mixing ratios in the middle and upper troposphere.

  6. ENVIRONMENTAL AND SUSTAINABLE TECHNOLOGY EVALUATION: BIOMASS CO-FIRING IN INDUSTRIAL BOILERS--MINNESOTA POWER'S RAPIDS ENERGY CENTER

    EPA Science Inventory

    The U.S. EPA operates the Environmental and Sustainable Technology Evaluation (ESTE) program to facilitate the deployment of innovative technologies through performance verification and information dissemination. This ESTE project involved evaluation of co-firing common woody bio...

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

    NASA Astrophysics Data System (ADS)

    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

  8. Decreased PCDD/F formation when co-firing a waste fuel and biomass in a CFB boiler by addition of sulphates or municipal sewage sludge

    SciTech Connect

    Åmand, Lars-Erik; Kassman, Håkan

    2013-08-15

    Highlights: • Two strategies to reduce PCDD/F formation when co-firing solid recovered fuel (SRF) and biomass. • They were co-combustion with municipal sewage sludge (MSS) and addition of ammonium sulphate. • PCDD/Fs were significantly reduced for a biomass rich in chlorine when adding ammonium sulphate. • MSS had a suppressing effect on PCDD/F formation during co-combustion with SRF. • A link is presented between gaseous alkali chlorides, chlorine in deposits and PCDD/F formation. - Abstract: Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are formed during waste incineration and in waste-to-energy boilers. Incomplete combustion, too short residence times at low combustion temperatures (<700 °C), incineration of electronic waste and plastic waste containing chlorine are all factors influencing the formation of PCDD/Fs in boilers. The impact of chlorine and catalysing metals (such as copper and iron) in the fuel on PCDD/F formation was studied in a 12 MW{sub th} circulating fluidised bed (CFB) boiler. The PCDD/F concentrations in the raw gas after the convection pass of the boiler and in the fly ashes were compared. The fuel types were a so-called clean biomass with low content of chlorine, biomass with enhanced content of chlorine from supply of PVC, and solid recovered fuel (SRF) which is a waste fuel containing higher concentrations of both chlorine, and catalysing metals. The PCDD/F formation increased for the biomass with enhanced chlorine content and it was significantly reduced in the raw gas as well as in the fly ashes by injection of ammonium sulphate. A link, the alkali chloride track, is demonstrated between the level of alkali chlorides in the gas phase, the chlorine content in the deposits in the convection pass and finally the PCDD/F formation. The formation of PCDD/Fs was also significantly reduced during co-combustion of SRF with municipal sewage sludge (MSS) compared to when SRF was fired without MSS

  9. Spatiotemporal patterns of drought, fire, and insect disturbance and resulting biomass dynamics in forests of the southwestern US: Results from multiscale satellite image analysis, 1990-2011

    NASA Astrophysics Data System (ADS)

    Garrity, S. R.; Allen, C. D.; Brumby, S.; Hicke, J. A.; Meddens, A. J.; Williams, P.; Cai, M.; McDowell, N.

    2012-12-01

    Local, regional, and global climate change has the potential to significantly alter ecosystem structure and function through modifying species composition and range, biogeochemical cycles, and energy fluxes. Symptoms of climate-related changes in forests may be chronic (e.g., modified productivity of extant vegetation) or acute (e.g., tree mortality). Information on the timing, extent, type and severity of forest response to climate is critical for quantifying the consequences of climate change for the biosphere, but this information is currently lacking. Throughout the 2000s, the southwestern US has experienced drought, insect outbreaks and record-breaking fires. Our objective was to quantify the forest response to these disturbances. We used multitemporal (8-day to annual return frequency) satellite imagery at several spatial resolutions (ranging from < 1 m to 1 km pixel size), from QuickBird, WorldView-2, Landsat, and MODIS satellite sensors, to quantify the timing and extent of forest disturbance from 1990 to 2011. We also used annual Landsat scenes to temporally extend the 2000 National Biomass and Carbon Dataset to cover the 1990-2011 study period. Our results show that during the 1990s, when climate conditions were predominantly favorable for forests, disturbances were infrequent and isolated. Increased frequency and extent of disturbance across all forests types, ranging from arid juniper (Juniperus spp.) and piñon (Pinus edulis) woodlands to subalpine spruce (Picea spp.) and fir (Abies spp.) forests, was observed throughout the 2000s when climate conditions were less favorable for forests. Lower elevation forests experienced the greatest amount of non-fire disturbance in the early 2000s whereas disturbances in higher elevation forests predominantly occurred in the latter half of the 2000s. Although lower elevation forests experienced a greater aerial extent of non-fire disturbance, biomass loss was greatest in the higher elevation forests. We also found a

  10. 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

    USGS Publications Warehouse

    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

  11. Closed-loop biomass co-firing. Quarterly technical progress report for the period October - December 1999

    SciTech Connect

    Jakeway, Lee; Nakahata, Mae

    2000-01-01

    Tasks included the following: analyze data from small plot harvests; large-scale planting of high-fiber cane variety; pilot-scale testing of fuel blends; procuring harvest equipment; perform harvest and co-firing trials for full-scale demonstration.

  12. Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

    NASA Astrophysics Data System (ADS)

    Le Breton, M.; Bacak, A.; Muller, J. B. A.; O'Shea, S. J.; Xiao, P.; Ashfold, M. N. R.; Cooke, M. C.; Batt, R.; Shallcross, D. E.; Oram, D. E.; Forster, G.; Bauguitte, S. J.-B.; Percival, C. J.

    2013-09-01

    A chemical ionisation mass spectrometer (CIMS) was developed for measuring hydrogen cyanide (HCN) from biomass burning events in Canada using I- reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO) and acetonitrile (CH3CN) was observed, indicating the potential of HCN as a biomass burning (BB) marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume-defining techniques employing CO and CH3CN measurements. The 6-sigma technique produced the highest R2 values for correlations with CO. A normalised excess mixing ratio (NEMR) of 3.68 ± 0.149 pptv ppbv-1 was calculated, which is within the range quoted in previous research (Hornbrook et al., 2011). The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work, the emission total for HCN from BB was 0.92 Tg (N) yr-1.

  13. Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

    NASA Astrophysics Data System (ADS)

    Le Breton, M.; Bacak, A.; Muller, J. B. A.; O'Shea, S. J.; Xiao, P.; Ashfold, M. N. R.; Cooke, M. C.; Batt, R.; Shallcross, D. E.; Oram, D. E.; Forster, G.; Bauguitte, S. J.-B.; Percival, C. J.

    2013-02-01

    A Chemical Ionisation Mass Spectrometer (CIMS) was developed for measuring hydrogen cyanide (HCN) from biomass burning events in Canada using I- reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO) and acetonitrile (CH3CN) was observed, indicating the potential of HCN as a biomass burning (BB) marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume defining techniques employing CO and CH3CN measurements. The 6 sigma technique produced the highest R2 values for correlations with CO. A Normalised Excess Mixing Ratio (NEMR) of 3.76 ± 0.022 pptv ppbv-1 was calculated which is within the range quoted in previous research (Hornbrook et al., 2011). The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work the emission total for HCN from BB was 0.92 Tg (N) yr-1.

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

    SciTech Connect

    Larry G. Felix; P. Vann Bush

    2001-07-17

    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.

  15. Decreased PCDD/F formation when co-firing a waste fuel and biomass in a CFB boiler by addition of sulphates or municipal sewage sludge.

    PubMed

    Åmand, Lars-Erik; Kassman, Håkan

    2013-08-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are formed during waste incineration and in waste-to-energy boilers. Incomplete combustion, too short residence times at low combustion temperatures (<700 °C), incineration of electronic waste and plastic waste containing chlorine are all factors influencing the formation of PCDD/Fs in boilers. The impact of chlorine and catalysing metals (such as copper and iron) in the fuel on PCDD/F formation was studied in a 12 MW(th) circulating fluidised bed (CFB) boiler. The PCDD/F concentrations in the raw gas after the convection pass of the boiler and in the fly ashes were compared. The fuel types were a so-called clean biomass with low content of chlorine, biomass with enhanced content of chlorine from supply of PVC, and solid recovered fuel (SRF) which is a waste fuel containing higher concentrations of both chlorine, and catalysing metals. The PCDD/F formation increased for the biomass with enhanced chlorine content and it was significantly reduced in the raw gas as well as in the fly ashes by injection of ammonium sulphate. A link, the alkali chloride track, is demonstrated between the level of alkali chlorides in the gas phase, the chlorine content in the deposits in the convection pass and finally the PCDD/F formation. The formation of PCDD/Fs was also significantly reduced during co-combustion of SRF with municipal sewage sludge (MSS) compared to when SRF was fired without MSS as additional fuel. PMID:23684693

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

    NASA Astrophysics Data System (ADS)

    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.

    PubMed

    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

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

    PubMed Central

    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 (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. PMID:23365540

  19. Air emission regulations for small to moderate sized wood-fired boilers: Final report: Northeast Regional Biomass Program

    SciTech Connect

    Bradley, M.J.; Tennis, M.W.

    1985-01-01

    Potential commercial wood burners in the Northeast hold the general perception that air pollution regulations pose special difficulties for them. This notion is based on incomplete information regarding the regulations in place and their applicability to small to moderate sized commercial faciliaties (ie. <100 mmBtu/hr). This study was commission by the Coalition of Northeastern Governors (CONEG) Policy Research Center, Inc., under the Northeast Regional Biomass Program, to provide a review of the air quality regulations effecting commercial wood burning installations, specifically identifying those regulations applying to the small to medium size units. This report provides an organized regulatory comparison to relate the different state emission rates with various levels of control techniques. 3 refs., 11 figs., 3 tabs.

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

    NASA Astrophysics Data System (ADS)

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

    SciTech Connect

    Larry G. Felix; P. Vann Bush

    2002-01-31

    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.

  2. Multilayer diffraction grating

    DOEpatents

    Barbee, Jr., Troy W.

    1990-01-01

    This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages.

  3. Multilayer diffraction grating

    DOEpatents

    Barbee, T.W. Jr.

    1990-04-10

    This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages. 2 figs.

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

    NASA Astrophysics Data System (ADS)

    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.

    2014-12-01

    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, and could

  5. Renewable liquid reflection grating

    DOEpatents

    Ryutov, Dmitri D.; Toor, Arthur

    2003-10-07

    A renewable liquid reflection grating. Electrodes are operatively connected to a conducting liquid in an arrangement that produces a reflection grating and driven by a current with a resonance frequency. In another embodiment, the electrodes create the grating by a resonant electrostatic force acting on a dielectric liquid.

  6. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, Michael D.; Britten, Jerald A.; Nguyen, Hoang T.; Boyd, Robert; Shore, Bruce W.

    1999-01-01

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described.

  7. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, M.D.; Britten, J.A.; Nguyen, H.T.; Boyd, R.; Shore, B.W.

    1999-05-25

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described. 7 figs.

  8. Atmospheric Effects of Biomass Burning

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.

    2000-01-01

    Biomass fires are both natural and anthropogenic in origin. The natural trigger is lightning, which leads to mid- and high-latitude fires and episodes of smoke and pollution associated with them. Lightning is also prominent in tropical regions when the dry season gives way to the wet season and lightning in convective systems ignites dry vegetation. Atmospheric consequences of biomass fires are complex. When considering the impacts of fires for a given ecosystem, inputs of fires must be compared to other process that emit trace gases and particles into the atmosphere. Other processes include industrial activity, fires for household purposes and biogenic sources which may themselves interact with fires. That is, fires may promote or restrict biogenic processes. Several books have presented various aspects of fire interactions with atmospheric chemistry and a cross-disciplinary review of a 1992 fire-oriented experiment appears in SAFARI: The Role of southern African Fires in Atmospheric and Ecological Environments. The IGAC/BIBEX core activity (see acronyms at end of Chapter) has sponsored field campaigns that integrate multiple aspects of fires ground-based measurements with an ecological perspective, atmospheric measurements with chemical and meteorological components, and remote sensing. This Chapter presents two aspects of biomass fires and the environment. Namely, the relationship between biomass burning and ozone is described, starting with a brief description of the chemical reactions involved and illustrative measurements and interpretation. Second, because of the need to observe biomass burning and its consequences globally, a summary of remote sensing approaches to the study of fires and trace gases is given. Examples in this Chapter are restricted to tropical burning for matters of brevity and because most burning activity globally is within this zone.

  9. Moderate Image Spectrometer (MODIS) Fire Radiative Energy: Physics and Applications

    NASA Technical Reports Server (NTRS)

    Kaufman, Y.

    2004-01-01

    MODIS fire channel does not saturate in the presence of fires. The fire channel therefore is used to estimate the fire radiative energy, a measure of the rate of biomass consumption in the fire. We found correlation between the fire radiative energy, the rate of formation of burn scars and the rate of emission of aerosol from the fires. Others found correlations between the fire radiative energy and the rate of biomass consumption. This relationships can be used to estimates the emissions from the fires and to estimate the fire hazards.

  10. Circulating fluidized bed tehnology in biomass combustion-performance, advances and experiences

    SciTech Connect

    Mutanen, K.I.

    1995-11-01

    Development of fluidized bed combustion (FBC) was started both in North America and in Europe in the 1960`s. In Europe and especially in Scandinavia the major driving force behind the development was the need to find new more efficient technologies for utilization of low-grade fuels like different biomasses and wastes. Both bubbling fluidized bed (BFB) and circulating fluidized bed (CFB) technologies were under intensive R&D,D efforts and have now advanced to dominating role in industrial and district heating power plant markets in Europe. New advanced CFB designs are now entering the markets. In North America and especially in the US the driving force behind the FBC development was initially the need to utilize different types of coals in a more efficient and environmentally acceptable way. The present and future markets seem to be mainly in biomass and multifuel applications where there is benefit from high combustion efficiency, high fuel flexibility and low emissions such as in the pulp and paper industry. The choice between CFB technology and BFB technology is based on selected fuels, emission requirements, plant size and on technical and economic feasibility. Based on Scandinavian experience there is vast potential in the North American industry to retrofit existing oil fired, pulverized coal fired, chemical recovery or grate fired boilers with FBC systems or to build a new FBC based boiler plant. This paper will present the status of CFB technologies and will compare technical and economic feasibility of CFB technology to CFB technology to BFB and also to other combustion methods. Power plant projects that are using advanced CFB technology e.g. Ahlstrom Pyroflow Compact technology for biomass firing and co-firing of biomass with other fuels will also be introduced.

  11. 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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

    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 the vast majority of the fuel is burned in this stage. Our fire averaged emission ratios and factors for CO2 and CH4

  12. Reflective diffraction grating

    DOEpatents

    Lamartine, Bruce C.

    2003-06-24

    Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

  13. 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

    NASA Astrophysics Data System (ADS)

    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

  14. Bidirectional grating compressors

    NASA Astrophysics Data System (ADS)

    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.

  15. A method for smoke marker measurements and its potential application for determining the contribution of biomass burning from wildfires and prescribed fires to ambient PM2.5 organic carbon

    NASA Astrophysics Data System (ADS)

    Sullivan, A. P.; Holden, A. S.; Patterson, L. A.; McMeeking, G. R.; Kreidenweis, S. M.; Malm, W. C.; Hao, W. M.; Wold, C. E.; Collett, J. L.

    2008-11-01

    Biomass burning is an important source of particulate organic carbon (OC) in the atmosphere. Quantifying this contribution in time and space requires a means of routinely apportioning contributions of smoke from biomass burning to OC. Smoke marker (for example, levoglucosan) measurements provide the most common approach for making this determination. A lack of source profiles for wildfires and prescribed fires and the expense and complexity of traditional smoke marker measurement methods have thus far limited routine estimates of these contributions to ambient aerosol concentrations and regional haze. We report here on the collection of source profiles for combustion of numerous wildland fuels and on the development of an inexpensive and robust technique for routine smoke marker measurements. Hi-Volume filter source samples were collected during two studies at the Fire Science Laboratory in Missoula, MT in 2006 and 2007. Levoglucosan (and other carbohydrates) were measured in these samples using high-performance anion-exchange chromatography with pulsed amperometric detection. Results of this analysis along with water-soluble potassium, OC, and elemental carbon are presented. The results show that emissions of levoglucosan are fairly correlated with OC with an average ratio of 0.031 μg C/μg C. Further, there was a definite pattern that emerged based on fuel component burned with the typical levoglucosan/OC ratio of branches > straw > needles > leaves. Additionally, this carbohydrate measurement method appears to provide fingerprint information about the type of fuel burned that could help constrain profiles chosen for aerosol source apportionment and lead to a better determination of source contributions from biomass burning.

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

    SciTech Connect

    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.

  17. Spherical grating spectrometers

    NASA Astrophysics Data System (ADS)

    O'Donoghue, Darragh; Clemens, J. Christopher

    2014-07-01

    We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

  18. Biomass power in transition

    SciTech Connect

    Marshall, D.K.

    1996-12-31

    Electricity production from biomass fuel has been hailed in recent years as an environmentally acceptable energy source that delivers on its promise of economically viable renewable energy. A Wall Street Journal article from three years ago proclaimed wood to be {open_quotes}moving ahead of costly solar panels and wind turbines as the leading renewable energy alternative to air-fouling fossils fuels and scary nuclear plants.{close_quotes} Biomass fuel largely means wood; about 90% of biomass generated electricity comes from burning waste wood, the remainder from agricultural wastes. Biomass power now faces an uncertain future. The maturing of the cogeneration and independent power plant market, restructuring of the electric industry, and technological advances with power equipment firing other fuels have placed biomass power in a competitive disadvantage with other power sources.

  19. Metal nanowire grating patterns.

    PubMed

    Kulkarni, G U; Radha, B

    2010-10-01

    Metal nanowire patterning in the form of grating structures has been carried out using a wide range of lithography techniques, and many hybrid methods derived from them. The challenge is to achieve sub-100 nm linewidths with controllable spacing and thickness over large areas of substrates with high throughput. In particular, the patterns with linewidth and spacing of a few tens of nm offer properties of great interest in optoelectronics and plasmonics. Crossbar grating structures--two gratings patterned perpendicular to each other--will play an important role as ultra-high density electrode grids in memristive devices for non-volatile memory. PMID:20945550

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

    NASA Astrophysics Data System (ADS)

    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

  1. Electrically-programmable diffraction grating

    DOEpatents

    Ricco, Antonio J.; Butler, Michael A.; Sinclair, Michael B.; Senturia, Stephen D.

    1998-01-01

    An electrically-programmable diffraction grating. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers).

  2. Color separation gratings

    NASA Technical Reports Server (NTRS)

    Farn, Michael W.; Knowlden, Robert E.

    1993-01-01

    In this paper, we describe the theory, fabrication and test of a binary optics 'echelon'. The echelon is a grating structure which separates electromagnetic radiation of different wavelengths, but it does so according to diffraction order rather than by dispersion within one diffraction order, as is the case with conventional gratings. A prototype echelon, designed for the visible spectrum, is fabricated using the binary optics process. Tests of the prototype show good agreement with theoretical predictions.

  3. Fluidized bed boiler having a segmented grate

    DOEpatents

    Waryasz, Richard E.

    1984-01-01

    A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.

  4. Combined grate and hot water heater

    SciTech Connect

    Milano, E.

    1984-09-25

    A combined grate and hot water heater for a fireplace which can be easily fabricated using conventional parts, easily installed and easily used is disclosed. The combined grate and hot water heater includes a rectangular shaped cradle for holding combustible materials to be burned which is sized and configured to fit into the fire chamber of the fireplace and a set of supporting legs for supporting the cradle on the floor of the fire chamber in spaced apart relationship. The cradle is made of a plurality of longitudinally extending and laterally extending heavy duty cast iron pipes interconnected by suitable pipe couplings so as to be in fluid communication with one another. A water inlet pipe and a water outlet pipe are connected to and in fluid communication with the pipes in the cradle for supplying water to be heated into the pipes and then allowing exit of the water after it has circulated through the pipes and has been heated by the fire produced on burning of the combustible materials. An inverted U shaped pipe section also made of heavy duty cast iron is coupled in fluid communication with the pipes in the cradle and extends vertically upward into the flue of the fireplace to utilize the heat present in the flue to further heat the water circulated through the pipes.

  5. INTERIOR DETAIL, STOVE. SMALL CHARCOAL FIRES WERE LIT IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR DETAIL, STOVE. SMALL CHARCOAL FIRES WERE LIT IN THE DEPRESSIONS, WHICH WERE COVERED WITH IRON GRATES TO SUSPEND POTS OVER THE HEAT SOURCE - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

  6. Regulation possibilities of biomass combustion

    NASA Astrophysics Data System (ADS)

    Suzdalenko, Vera; Gedrovics, Martins; Zake, Maija; Barmina, Inesa

    2012-11-01

    The focus of the recent experimental research is to analyze the regulation possibilities of biomass combustion. Three possibilities were chosen as part of this research: a) biomass cofiring with propane, b) swirling flow with re-circulation zone, and c) use of a permanent magnet. The aim of the research is to provide stable, controllable and effective biomass combustion with minimum emissions. The special pilot device was created where biomass can be combusted separately and co-fired with propane. Wood pellets were used during the experiments.

  7. High divergent 2D grating

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Ma, Jianyong; Zhou, Changhe

    2014-11-01

    A 3×3 high divergent 2D-grating with period of 3.842μm at wavelength of 850nm under normal incidence is designed and fabricated in this paper. This high divergent 2D-grating is designed by the vector theory. The Rigorous Coupled Wave Analysis (RCWA) in association with the simulated annealing (SA) is adopted to calculate and optimize this 2D-grating.The properties of this grating are also investigated by the RCWA. The diffraction angles are more than 10 degrees in the whole wavelength band, which are bigger than the traditional 2D-grating. In addition, the small period of grating increases the difficulties of fabrication. So we fabricate the 2D-gratings by direct laser writing (DLW) instead of traditional manufacturing method. Then the method of ICP etching is used to obtain the high divergent 2D-grating.

  8. Biomass Burning

    Atmospheric Science Data Center

    2015-07-27

    Projects:  Biomass Burning Definition/Description:  Biomass Burning: This data set represents the geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ...

  9. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-09-02

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  10. Fire severity influences the response of soil microbes to a boreal forest fire

    NASA Astrophysics Data System (ADS)

    Holden, Sandra R.; Rogers, Brendan M.; Treseder, Kathleen K.; Randerson, James T.

    2016-03-01

    Wildfire activity is projected to increase in boreal forests as a result of climate warming. The consequences of increased wildfire activity for soil carbon (C) storage in boreal forests may depend on the sensitivity of soil microbes to fire severity, but microbial responses to boreal forest fire severity are not well known. Here, we combine remote sensing of fire severity and field sampling to characterize the response of soil microbial biomass per g soil, microbial respiration of CO2 per g soil, and fungal groups to fire severity in a boreal forest ecosystem. We used remote sensing measurements of differenced normalized burn ratio from Landsat as a measure of fire severity. Our results demonstrate that fire severity controls soil microbial responses to boreal forest fires. In comparison to unburned stands, burned stands had a 52% and 56% reduction in soil microbial biomass and basal respiration, respectively. Within burned stands, we found that microbial biomass and basal respiration significantly declined with increasing fire severity. In addition, mycorrhizal taxa and basidiomycetes displayed particularly low tolerances for severe fire. Although wildfires result in the immediate loss of soil C, our study provides evidence that decreases in microbial biomass and respiration following high severity fires may reduce the capacity of the soil microbial community to decompose soil C over longer time scales. Therefore, models of C cycle responses to climate warming may need to represent the sensitivity of microbial biomass and fungal community composition to fire severity in boreal forests.

  11. Modeling the Optical Properties of Biomass Burning Aerosols: Young Smoke Aerosols From Savanna Fires and Comparisons to Observations from SAFARI 2000

    NASA Technical Reports Server (NTRS)

    Matichuk, R. I.; Smith, J. A.; Toon, O. B.; Colarso, P. R.

    2006-01-01

    Annually, farmers in southern Africa manage their land resources and prepare their fields for cultivation by burning crop residual debris, with a peak in the burning season occurring during August and September. The emissions from these fires in southern Africa are among the greatest from fires worldwide, and the gases and aerosol particles produced adversely affect air quality large distances from their source regions, and can even be tracked in satellite imagery as they cross the Atlantic and Pacific Ocean basins. During August and September 2000 an international group of researchers participating in the Southern African Regional Science Initiate field experiment (SAFARI 2000) made extensive ground-based, airborne, and satellite measurements of these gases and aerosols in order to quantify their amounts and effects on Earth's atmosphere. In this study we interpreted the measurements of smoke aerosol particles made during SAFARI 2000 in order to better represent these particles in a numerical model simulating their transport and fate. Typically, smoke aerosols emitted from fires are concentrated by mass in particles about 0.3 micrometers in diameter (1,000,000 micrometers = 1 meter, about 3 feet); for comparison, the thickness of a human hair is about 50 micrometers, almost 200 times as great. Because of the size of these particles, at the surface they can be easily inhaled into the lungs, and in high concentrations have deleterious health effects on humans. Additionally, these particles reflect and absorb sunlight, impacting both visibility and the balance of sunlight reaching -Earth's surface, and ultimately play a role in modulating Earth's climate. Because of these important effects, it is important that numerical models used to estimate Earth's climate response to changes in atmospheric composition accurately represent the quantity and evolution of smoke particles. In our model, called the Community Aerosol and Radiation Model for Atmospheres (CARMA) we used

  12. Electrically-programmable diffraction grating

    DOEpatents

    Ricco, A.J.; Butler, M.A.; Sinclair, M.B.; Senturia, S.D.

    1998-05-26

    An electrically-programmable diffraction grating is disclosed. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers). 14 figs.

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

    SciTech Connect

    J. Rabovitser; B. Bryan; S. Wohadlo; S. Nester; J. Vaught; M. Tartan L. Szymanski; R. Glickert

    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.

  14. Charged particle accelerator grating

    DOEpatents

    Palmer, R.B.

    1985-09-09

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  15. The Cryogenic Grating Spectrometer

    NASA Technical Reports Server (NTRS)

    Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean W. J.; Simpson, Janet P.; Rubin, Robert H.

    1995-01-01

    The Cryogenic Grating Spectrometer (CGS) first flew on the KAO in 1982 December and has been open to guest investigators since 1984 October. In the past 12 years it has completed over 100 research flights supporting 13 different principal investigators studying a variety of objects. We briefly describe the instrument, its capabilities and accomplishments, and acknowledge the people who have contributed to its development and operation.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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 through

  18. Characterization of pinhole transmission gratings.

    PubMed

    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

  19. Biomass pretreatment

    SciTech Connect

    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.

  20. BIOMASS UTILIZATION

    EPA Science Inventory

    The biomass utilization task consists of the evaluation of a biomass conversion technology including research and development initiatives. The project is expected to provide information on co-control of pollutants, as well as, to prove the feasibility of biomass conversion techn...

  1. 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

    NASA Astrophysics Data System (ADS)

    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

  2. Biomass Logistics

    SciTech Connect

    J. Richard Hess; Kevin L. Kenney; William A. Smith; Ian Bonner; David J. Muth

    2015-04-01

    Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in quantifying multi-factor sustainability limits to increase removal rate as guided by sustainable residue removal plans, and mitigating soil contamination through targeted removal rates based on soil type and residue type/fraction is allowing the use of new high efficiency harvesting equipment and methods. As another consideration, single pass harvesting and other technologies that improve harvesting costs cause biomass storage moisture management challenges, which challenges are further perturbed by annual variability in biomass moisture content. Monitoring, sampling, simulation, and analysis provide basis for moisture, time, and quality relationships in storage, which has allowed the development of moisture tolerant storage systems and best management processes that combine moisture content and time to accommodate baled storage of wet material based upon “shelf-life.” The key to improving biomass supply logistics costs has been developing the associated agronomic sustainability and biomass quality technologies and processes that allow the implementation of equipment engineering solutions.

  3. Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

    NASA Astrophysics Data System (ADS)

    Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

    2013-05-01

    Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments

  4. Proton Transfer Reaction Time-of-Flight Mass Spectrometric (PTR-TOF-MS) determination of volatile organic compounds (VOCs) emitted from a biomass fire developed under stable nocturnal conditions

    NASA Astrophysics Data System (ADS)

    Brilli, Federico; Gioli, Beniamino; Ciccioli, Paolo; Zona, Donatella; Loreto, Francesco; Janssens, Ivan A.; Ceulemans, Reinhart

    2014-11-01

    Combustion of solid and liquid fuels is the largest source of potentially toxic volatile organic compounds (VOCs), which can strongly affect health and the physical and chemical properties of the atmosphere. Among combustion processes, biomass burning is one of the largest at global scale. We used a Proton Transfer Reaction “Time-of-Flight” Mass Spectrometer (PTR-TOF-MS), which couples high sensitivity with high mass resolution, for real-time detection of multiple VOCs emitted by burned hay and straw in a barn located near our measuring station. We detected 132 different organic ions directly attributable to VOCs emitted from the fire. Methanol, acetaldehyde, acetone, methyl vinyl ether (MVE), acetic acid and glycolaldehyde dominated the VOC mixture composition. The time-course of the 25 most abundant VOCs, representing ∼85% of the whole mixture of VOCs, was associated with that of carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) emissions. The strong linear relationship between the concentrations of pyrogenic VOC and of a reference species (i.e. CO) allowed us to compile a list of emission ratios (ERs) and emission factors (EFs), but values of ER (and EF) were overestimated due to the limited mixing of the gases under the stable (non-turbulent) nocturnal conditions. In addition to the 25 most abundant VOCs, chemical formula and concentrations of the residual, less abundant VOCs in the emitted mixture were also estimated by PTR-TOF-MS. Furthermore, the evolution of the complex combustion process was described on the basis of the diverse types of pyrogenic gases recorded.

  5. Fibre gratings and their applications

    SciTech Connect

    Vasil'ev, Sergei A; Medvedkov, O I; Korolev, I G; Bozhkov, A S; Kurkov, Andrei S; Dianov, Evgenii M

    2005-12-31

    A brief review is given of the state of the art in the research on the photosensitivity of fibres and photoinduced fibre gratings. The most important properties of fibre gratings are considered and the main methods of their production and their applications are discussed. The photosensitive compositions of silica glasses are presented and methods for increasing their photosensitivity are indicated. (review)

  6. Biomass power for rural development. Revised design report.

    SciTech Connect

    Neuhauser, Edward

    1999-10-03

    The retrofit of Dunkirk Steam Station to fire biomass fuels is an important part of the Consortium's goal--demonstrating the viability of commercial scale willow energy crop production and conversion to power. The goal for th biomass facilities at Dunkirk is to reliably cofire a combination of wood wastes and willow biomass with coal at approximately 20% by heat input.

  7. Phononic crystal diffraction gratings

    NASA Astrophysics Data System (ADS)

    Moiseyenko, Rayisa P.; Herbison, Sarah; Declercq, Nico F.; Laude, Vincent

    2012-02-01

    When a phononic crystal is interrogated by an external source of acoustic waves, there is necessarily a phenomenon of diffraction occurring on the external enclosing surfaces. Indeed, these external surfaces are periodic and the resulting acoustic diffraction grating has a periodicity that depends on the orientation of the phononic crystal. This work presents a combined experimental and theoretical study on the diffraction of bulk ultrasonic waves on the external surfaces of a 2D phononic crystal that consists of a triangular lattice of steel rods in a water matrix. The results of transmission experiments are compared with theoretical band structures obtained with the finite-element method. Angular spectrograms (showing frequency as a function of angle) determined from diffraction experiments are then compared with finite-element simulations of diffraction occurring on the surfaces of the crystal. The experimental results show that the diffraction that occurs on its external surfaces is highly frequency-dependent and has a definite relation with the Bloch modes of the phononic crystal. In particular, a strong influence of the presence of bandgaps and deaf bands on the diffraction efficiency is found. This observation opens perspectives for the design of efficient phononic crystal diffraction gratings.

  8. Understory Fires

    NASA Video Gallery

    The flames of understory fires in the southern Amazon reach on average only a few feet tall, but the fire type can claim anywhere from 10 to 50 percent of a burn area's trees. Credit: NASA/Doug Morton

  9. Texas Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Wind-Whipped Fires in East Texas     View Larger Image ... western side of the storm stoked fires throughout eastern Texas, which was already suffering from the worst one-year drought on record ...

  10. Fire Detector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    An early warning fire detection sensor developed for NASA's Space Shuttle Orbiter is being evaluated as a possible hazard prevention system for mining operations. The incipient Fire Detector represents an advancement over commercially available smoke detectors in that it senses and signals the presence of a fire condition before the appearance of flame and smoke, offering an extra margin of safety.

  11. Aerosol emissions by tropical forest and savanna biomass burning: Characteristic trace elements and fluxes

    SciTech Connect

    Echalar, F.; Gaudichet, A.; Cachier, H.

    1995-11-15

    This report characterizes and compares trace element emissions from fires of three different types of savannas and from the southwestern amazonian rain forest. This study tries to verify a fingerprint that may characterize savanna fires or tropical biomass burning.

  12. Formation, composition and particle size distribution of fly-ashes from biomass combustion plants

    SciTech Connect

    Brunner, T.; Dahl, J.; Obernberger, I.

    1998-12-31

    dominant. The particle size distribution of aerosols formed in grate combustion systems is unimodal and has a distinct peak in the range < 1{micro}m without major variations between different biomass fuels. For bark, wood chips and sawdust the major amount of aerosols appears in the range of approximately 0.1{micro}m (Stokes diameter). The dominating particle size of aerosols formed during straw combustion is about 0.5{micro}m. Concerning the combustion of wood and bark, no significant influence of the fuel particle size, the combustion temperature and the boiler load on the size distribution of aerosols was detected for wood and bark in grate furnaces. However, the total amount of aerosols formed by different biomass fuels differs considerably and can be explained by the varying amounts of volatile alkali metals (mainly K and Na), sulfur and chloride in the fuels. That is, the combustion of straw displays total aerosol amounts of up to 900 mg/Nm{sup 3} (related to dry flue gas and 13 Vol.% O{sub 2}) which is about 10 times higher than the emissions of bark- and hardwood-fired grate combustion units. A second influencing parameter revealed is the temperature of combustion. Raising combustion temperatures increase the total amount of aerosols formed.

  13. Fiber Grating Environmental Sensing System

    DOEpatents

    Schulz, Whitten L.; Udd, Eric

    2003-07-29

    Fiber grating environmental measurement systems are comprised of sensors that are configured to respond to changes in moisture or chemical content of the surrounding medium through the action of coatings and plates inducing strain that is measured. These sensors can also be used to monitor the interior of bonds for degradation due to aging, cracking, or chemical attack. Means to multiplex these sensors at high speed and with high sensitivity can be accomplished by using spectral filters placed to correspond to each fiber grating environmental sensor. By forming networks of spectral elements and using wavelength division multiplexing arrays of fiber grating sensors may be processed in a single fiber line allowing distributed high sensitivity, high bandwidth fiber optic grating environmental sensor systems to be realized.

  14. 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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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 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 improvement of

  15. Stretchable diffraction gratings for spectrometry

    NASA Astrophysics Data System (ADS)

    Simonov, Aleksey N.; Grabarnik, Semen; Vdovin, Gleb

    2007-07-01

    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 changed by mechanical stretching. When used in a monochromator with two slits, the stretchable grating permits scanning the spectral components over the output slit, converting the monochromator into a scanning spectrometer. The spectral resolution of such a spectrometer was found to be limited mainly by the wave-front aberrations due to the grating deformation. A model relating the deformation-induced aberrations in different diffraction orders is presented. In the experiments, a 12-mm long viscoelastic grating with a spatial frequency of 600 line pairs/mm provided a full-width at half-maximum resolution of up to ~1.2 nm in the 580-680 nm spectral range when slowly stretched by a micrometer screw and ~3 nm when repeatedly stretched by a voice coil at 15 Hz. Comparison of aberrations in transmitted and diffracted beams measured by a Shack- Hartmann wave-front sensor showed that astigmatisms caused by stretch-dependent wedge deformation are the main factors limiting the resolution of the viscoelastic-grating-based spectrometer.

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

    NASA Technical Reports Server (NTRS)

    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.

  17. Diffraction gratings for optical sensing

    NASA Astrophysics Data System (ADS)

    Lu, Patrick P.

    The following document summarizes a journey through the world of diffraction gratings, covering topics such as their history, fabrication, metrology, and uses in some of the most precise scientific experiments ever proposed. Though diffraction gratings have long been used for spectroscopy and pulse compression, it was not until recently that researchers have explored their ability to split and recombine single-frequency CW laser sources for high-precision interferometry. Gravitational-wave detection, one of the most challenging sensing applications to date, is being investigated by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Laser Interferometer Space Antenna (LISA) projects. Future generations of LIGO and LISA detectors may incorporate gratings as key optical components. This thesis describes the ways gratings can improve interferometer performance by simplifying thermal management and discusses the essential challenges that must be overcome before they can be adopted. The use of gratings requires new interferometer geometries. We show cases where these can be implemented simply and compactly. Gravitational-wave interferometry imposes many requirements on grating components. Using improved metrology methods, we demonstrate that large dielectric gratings with uniformly high efficiency can be fabricated and validated. In particular, we measure the diffraction efficiency of two 20-cm-scale gratings over their entire apertures. The values taken from across their surfaces collectively had means and standard deviations of mu = 99.293% and sigma = 0.164%, and mu =99.084% and sigma =0.079%. We also present simplified models of thermal distortions in gratings, and show them to be in good agreement with measurements conducted by a wavefront sensor. Special focus is given to experimental demonstrations that have achieved highly precise measurements of translational and rotational motion, also known as displacement and angular sensing. For the former

  18. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2006-01-01

    In 2005, six companies mined fire clay in Missouri, Ohio and South Carolina. Production was estimate to be 300 kt with a value of $8.3 million. Missouri was the leading producer state followed by Ohio and South Carolina. For the third consecutive year, sales and use of fire clays have been relatively unchanged. For the next few years, sales of fire clay is forecasted to remain around 300 kt/a.

  19. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the fire clay industry, particularly in the U.S., as of June 2011. It claims that the leading fire clay producer in the U.S. is the state of Missouri. The other major producers include California, Texas and Washington. It reports that the use of heavy clay products made of fire clay like brick, cement and lightweight aggregate has increased slightly in 2010.

  20. Smouldering Subsurface Fires in the Earth System

    NASA Astrophysics Data System (ADS)

    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

  1. Theoretical analysis of novel fiber grating pair

    NASA Astrophysics Data System (ADS)

    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.

  2. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2013-01-01

    Four companies mined fire clay in three states in 2012. Production, based on a preliminary survey of the fire clay industry, was estimated to be 230 kt (254,000 st) valued at $6.98 million, an increase from 215 kt (237,000 st) valued at $6.15 million in 2011. Missouri was the leading producing state, followed by Colorado and Texas, in decreasing order by quantity. The number of companies mining fire clay declined in 2012 because several common clay producers that occasionally mine fire clay indicated that they did not do so in 2012.

  3. Cost assessment of biomass conversion technologies

    SciTech Connect

    Peterson, C.

    1982-06-01

    NYSERDA presents preliminary capital and operations/maintainence cost data from an assessment of the technologies to convert biomass. Moving grates and fluidized bed direct combustion cost data are calculated. The ''waterwall incineration'' is found to be the most economical. Gasification, of air and oxygen type, and pyrolysis, are calculated. Anaerobic digestion uses plug flow and single tank complete mix digesters. The plug flow cost data is derived. Fermentation of starch crops, cheese whey, and cellulose is studied, and cost data determined.

  4. Holographic Gratings for Optical Processing

    NASA Technical Reports Server (NTRS)

    Kukhtarev, Nickolai

    2002-01-01

    Investigation of astronomical objects and tracking of man-made space objects lead to generation of huge amount of information for optical processing. Traditional big-size optical elements (such as optical telescopes) have a tendency for increasing aperture size in order to improve sensitivity. This tendency leads to increasing of weight and costs of optical systems and stimulate search for the new, more adequate technologies. One approach to meet these demands is based on developing of holographic optical elements using new polymeric materials. We have investigated possibility to use new material PQ-PMMA (phenantrenequinone-doped PMMA (Polymethyl Methacrylate)) for fabrication of highly selective optical filters and fast spatial-temporal light modulators. This material was originally developed in Russia and later was tested in CalTech as a candidate material for optical storage. Our theoretical investigation predicts the possibility of realization of fast spatial and temporal light modulation, using volume reflection-type spectral filter. We have developed also model of holographic-grating recording in PQ-PMMA material, based on diffusional amplification. This mechanism of recording allow to receive high diffraction efficiency during recording of reflection-type volume holographic grating (holographic mirror). We also investigated recording of dynamic gratings in the photorefractive crystals LiNbO3 (LN) for space-based spectroscopy and for adaptive correction of aberrations in the telescope's mirrors. We have shown, that specific 'photogalvanic' mechanism of holographic grating recording in LN allow to realize recording of blazed gratings for volume and surface gratings. Possible applications of dynamic gratings in LN for amplification of images, transmitted through an imaging fiber guide was also demonstrated.

  5. Near-perfect diffraction grating rhomb

    DOEpatents

    Wantuck, Paul J.

    1990-01-01

    A near-perfect grating rhomb enables an output beam to be diffracted to an angle offset from the input beam. The correcting grating is tipped relative to the dispersing grating to provide the offset angle. The correcting grating is further provided with a groove spacing which differs from the dispersing grating groove space by an amount effective to substantially remove angular dispersion in the output beam. A near-perfect grating rhomb has the capability for selective placement in a FEL to suppress sideband instabilities arising from the FEL.

  6. Diffraction by dual-period gratings.

    PubMed

    Skigin, Diana C; Depine, Ricardo A

    2007-03-20

    The dynamical characteristics of dual-period perfectly conducting gratings are explored. Gratings with several grooves (reflection) or slits (transmission) within each period are considered. A scalar approach is proposed to derive the general characteristics of the diffracted response. It was found that compound gratings can be designed to cancel as well as to intensify a given diffraction order. These preliminary estimations for finite gratings are validated by numerical examples for infinitely periodic reflection and transmission gratings with finite thickness, performed using an extension of the rigorous modal method to compound gratings, for both polarization cases. PMID:17334426

  7. BIOMASS REBURNING - MODELING/ENGINEERING STUDIES

    SciTech Connect

    1998-10-20

    This project is designed to develop engineering and modeling tools for a family of NO{sub x} control technologies utilizing biomass as a reburning fuel. The forth reporting period (July 1 - September 30) included ongoing kinetic modeling of the reburning process while firing biomass. Modeling of biomass reburning concentrated on description of biomass performance at different reburning heat inputs. Reburning fuel was assumed to undergo rapid breakdown to produce various gaseous products. Modeling shows that the efficiency of biomass is affected by its composition. The kinetic model agrees with experimental data for a wide range of initial conditions and thus can be used for process optimization. Experimental data on biomass reburning are included in Appendix 2.

  8. Unprecedented Fires in Southern Africa

    NASA Technical Reports Server (NTRS)

    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

  9. Estimating fire radiative power obscuration by tree canopies through laboratory experiments: Estimating fire radiative energy in a longleaf pine forest from airborne thermal imagery

    NASA Astrophysics Data System (ADS)

    Mathews, William

    Remote sensing has been proven as a useful tool in characterizing the effects of fire on a landscape scale. The radiant energy released during biomass burning can be measured remotely, and is directly related to the rate biomass consumed from the fire. This is an important measurement as it can characterize fire effects on the ground along with provide important information about the amount of gases produced by the fire. One source of error associated with estimating the fire radiative energy (FRE) remotely is the obscuration of the signal by the forest canopy. We quantify the relationship between canopy cover and the amount of energy observed by a sensor rom laboratory experiments. A prescribed fire was conducted in northwestern Florida and a suite of pre-, active, and post-fire measurements were taken by an interdisciplinary team. From those data we measured the amount of biomass consumed by the fire FRE estimates.

  10. Fire Power

    ERIC Educational Resources Information Center

    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…

  11. Returning Fire

    ERIC Educational Resources Information Center

    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…

  12. Arizona Fires

    Atmospheric Science Data Center

    2014-05-15

    ... the second largest fire in Arizona history. More than 2,000 people are working to contain the fire, which is being driven by high winds and ... bright desert background. The areas with no data (shown in black and present at the oblique angles) are locations where the variable ...

  13. Siberian Fires

    Atmospheric Science Data Center

    2013-04-16

    ... of fires across Siberia and the Russian Far East, northeast China and northern Mongolia. Fires in Eastern Siberia have been increasing in ... spatial contrast. The heights correspond to elevations above sea level. Taking into account the surface elevation, the smoke plumes range ...

  14. Does prescribed fire benefit wetland vegetation?

    USGS Publications Warehouse

    Flores, C.; Bounds, D.L.; Ruby, D.E.

    2011-01-01

    The effects of fire on wetland vegetation in the mid-Atlantic region of the United States are poorly known, despite the historical use of fire by federal, state, and private landowners in the Chesapeake Bay Region. Prescribed fire is widely used by land managers to promote vegetation that is beneficial to migratory waterfowl, muskrats, and other native wildlife and to reduce competition from less desirable plant species. We compared vegetative response to two fire rotations, annual burns and 3-year burns, and two control sites, Control 1 and Control 2. We tested the effects of fire within six tidal marsh wetlands at Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management Area in Maryland. We examined changes in total live biomass (all species), total stem density, litter, and changes in live biomass and stem density of four dominant wetland plant species (11 variables). Our results suggest that annual prescribed fires will decrease the accumulation of litter, increase the biomass and stem densities of some wetland plants generally considered less desirable for wildlife, and have little or no effect on other wetland plants previously thought to benefit from fire. ?? 2011 US Government.

  15. Holocene fire dynamics in Fennoscandia

    NASA Astrophysics Data System (ADS)

    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

  16. FIELD TESTS OF INDUSTRIAL STOKER COAL-FIRED BOILERS FOR EMISSIONS CONTROL AND EFFICIENCY IMPROVEMENT--SITE I

    EPA Science Inventory

    The report gives results of field measurements made on a 70,000 lb steam/hr coal-fired overfeed stoker with traveling grate. The effects of various parameters on boiler emissions and efficiency were studied. Parameters include overfire air, excess oxygen, grate heat release, and ...

  17. FIELD TESTS OF INDUSTRIAL STOKER COAL-FIRED BOILERS FOR EMISSIONS CONTROL AND EFFICIENCY IMPROVEMENT - SITE K

    EPA Science Inventory

    The report gives results of field measurements made on a 50,000 lb stream/hr coal-fired overfeed stoker with traveling grate. The effects of various parameters on boiler emissions and efficiency were studied. Parameters include overfire air, excess oxygen, grate heat release, and...

  18. Biomass reburning - Modeling/engineering studies

    SciTech Connect

    Sheldon, M.; Marquez, A.; Zamansky, V.

    2000-07-27

    This project is designed to develop engineering and modeling tools for a family of NO{sub x} control technologies utilizing biomass as a reburning fuel. During the eleventh reporting period (April 1--June 30, 2000), EER and NETL R&D group continued to work on Tasks 2, 3, 4, and 5. This report includes results from Task 3 physical modeling of the introduction of biomass reburning in a working coal-fired utility boiler.

  19. Exploiting a Transmission Grating Spectrometer

    SciTech Connect

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  20. Diffraction by random Ronchi gratings.

    PubMed

    Torcal-Milla, Francisco Jose; Sanchez-Brea, Luis Miguel

    2016-08-01

    In this work, we obtain analytical expressions for the near-and far-field diffraction of random Ronchi diffraction gratings where the slits of the grating are randomly displaced around their periodical positions. We theoretically show that the effect of randomness in the position of the slits of the grating produces a decrease of the contrast and even disappearance of the self-images for high randomness level at the near field. On the other hand, it cancels high-order harmonics in far field, resulting in only a few central diffraction orders. Numerical simulations by means of the Rayleigh-Sommerfeld diffraction formula are performed in order to corroborate the analytical results. These results are of interest for industrial and technological applications where manufacture errors need to be considered. PMID:27505363

  1. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2010 CFR

    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...

  2. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 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...

  3. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 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...

  4. Recent progress in polymer optical fibre gratings

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Carroll, K.; Webb, D. J.; Bennion, I.; Kalli, K.; Emiliyanov, G.; Bang, O.; Kjær, E.; Peng, G. D.

    2008-04-01

    We describe our recent progress in polymer fibre Bragg grating technology, including the writing of the first FBGs in TOPAS cyclic olefin copolymer, enhancements to photosensitivity brought about by dopants and studies on grating annealing.

  5. Sensitivity of a laser-driven-grating linac to grating errors

    SciTech Connect

    Kroll, N.M.

    1982-04-01

    The effect of grating errors on transverse beam stability is analyzed. We characterize grating errors by random groove displacements and find that transverse displacements due to such errors approach limiting values of the same order as the grating displacements themselves. It therefore appears that transverse stability requirements will not impose unusually stringent precision requirements on the grating structure.

  6. Spacecraft Fire Safety

    NASA Technical Reports Server (NTRS)

    Margle, Janice M. (Editor)

    1987-01-01

    Fire detection, fire standards and testing, fire extinguishment, inerting and atmospheres, fire-related medical science, aircraft fire safety, Space Station safety concerns, microgravity combustion, spacecraft material flammability testing, and metal combustion are among the topics considered.

  7. Gratings for High-Energy Petawatt Lasers

    SciTech Connect

    Nguyen, H T; Britten, J A; Carlson, T C; Nissen, J D; Summers, L J; Hoaglan, C R; Aasen, M D; Peterson, J E; Jovanovic, I

    2005-11-08

    To enable high-energy petawatt laser operation we have developed the processing methods and tooling that produced both the world's largest multilayer dielectric reflection grating and the world's highest laser damage resistant gratings. We have successfully delivered the first ever 80 cm aperture multilayer dielectric grating to LLNL's Titan Intense Short Pulse Laser Facility. We report on the design, fabrication and characterization of multilayer dielectric diffraction gratings.

  8. Diffraction pattern of gratings with erosion

    NASA Astrophysics Data System (ADS)

    Olivares-Pérez, Arturo; Fuentes-Tapia, Israel

    2015-03-01

    We present a theoretical study of amplitude diffraction gratings using computer simulating, which consists of a random sampling of points on the image grating to determine the points to be plotted and the points to remove, to simulate erosion in amplitude on the grating. We show their behavior in the diffraction patterns and the induced noise by limiting the number of points that representing the image of the eroded gratings and their symmetry.

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

    PubMed

    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

  10. Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques

    NASA Astrophysics Data System (ADS)

    Chung, Kit Man

    Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one

  11. Diffraction gratings used as identifying markers

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1991-01-01

    A finely detailed defraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the defraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating.

  12. Embedded high-contrast distributed grating structures

    DOEpatents

    Zubrzycki, Walter J.; Vawter, Gregory A.; Allerman, Andrew A.

    2002-01-01

    A new class of fabrication methods for embedded distributed grating structures is claimed, together with optical devices which include such structures. These new methods are the only known approach to making defect-free high-dielectric contrast grating structures, which are smaller and more efficient than are conventional grating structures.

  13. Biomass energy

    SciTech Connect

    Smil, V.

    1983-01-01

    This book offers a broad, interdisciplinary approach to assessing the factors that are key determinants to the use of biomass energies, stressing their limitations, complexities, uncertainties, links, and consequences. Considers photosynthesis, energy costs of nutrients, problems with monoculture, and the energy analysis of intensive tree plantations. Subjects are examined in terms of environmental and economic impact. Emphasizes the use and abuse of biomass energies in China, India, and Brazil. Topics include forests, trees for energy, crop residues, fuel crops, aquatic plants, and animal and human wastes. Recommended for environmental engineers and planners, and those involved in ecology, systematics, and forestry.

  14. Mexico Fires

    Atmospheric Science Data Center

    2013-04-18

    article title:  Smoke from Fires in Southern Mexico     View Larger Image ... southern Mexico sent smoke drifting northward over the Gulf of Mexico. These views from the Multi-angle Imaging SpectroRadiometer (MISR) ...

  15. California Fires

    Atmospheric Science Data Center

    2014-05-15

    ... title:  Smoke from Station Fire Blankets Southern California     View Larger Image ... that had not burned in decades, and years of extended drought contributed to the explosive growth of wildfires throughout southern ...

  16. Emissions from Biomass Burning in the Yucatan

    NASA Technical Reports Server (NTRS)

    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.

  17. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2012-01-01

    Five companies mined fire clay in four states in 2011. Production, based on a preliminary survey of the fire clay industry, was estimated to be 240 kt (265,000 st), valued at $7.68 million, an increase from 216 kt (238,000 st), valued at $6.12 million in 2010. Missouri was the leading producing state, followed by Texas, Washington and Ohio, in decreasing order by quantity.

  18. New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations

    NASA Astrophysics Data System (ADS)

    Andela, N.; Kaiser, J. W.; van der Werf, G. R.; Wooster, M. J.

    2015-08-01

    cycle generally resulted in an overestimation of FRE, while including information on the climatology of the fire diurnal cycle improved FRE estimates. The approach based on knowledge of the climatology of the fire diurnal cycle also improved distribution of FRE over the day, although only when aggregating model results to coarser spatial and/or temporal scale good correlation was found with the full SEVIRI hourly reference data set. We recommend the use of regionally varying fire diurnal cycle information within the Global Fire Assimilation System (GFAS) used in the Copernicus Atmosphere Monitoring Services, which will improve FRE estimates and may allow for further reconciliation of biomass burning emission estimates from different inventories.

  19. Electromagnetically induced grating with maximal atomic coherence

    SciTech Connect

    Carvalho, Silvania A.; Araujo, Luis E. E. de

    2011-10-15

    We describe theoretically an atomic diffraction grating that combines an electromagnetically induced grating with a coherence grating in a double-{Lambda} atomic system. With the atom in a condition of maximal coherence between its lower levels, the combined gratings simultaneously diffract both the incident probe beam as well as the signal beam generated through four-wave mixing. A special feature of the atomic grating is that it will diffract any beam resonantly tuned to any excited state of the atom accessible by a dipole transition from its ground state.

  20. Compact Imaging Spectrometer Utilizing Immersed Gratings

    DOEpatents

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    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.

  1. Distributed etched diffraction grating demultiplexer

    NASA Astrophysics Data System (ADS)

    Jafari, Amir

    This doctoral thesis studies the concept of a distributed etched diffraction grating (DEDG) and presents a methodology to engineer the spectral response of the device. The design which incorporates a distributed Bragg reflector (DBR) at the facets of a conventional etched diffraction grating demultiplexer promises for a superior performance in multiple aspects. Where in a conventional etched diffraction grating, smooth vertical deep etched walls are required in order to realize a low insertion loss device; in the DEDG such requirement is significantly mitigated. Deep etched walls are replaced with shallowly etched diffraction grating facets followed by a DBR structure and as a result devices with significantly lower insertion loss are achievable. The feasibility of the application of DEDG as a wavelength demultiplexer was demonstrated through fabrication and characterization of a prototype device. The proof of concept device was fabricated using the state of the art deep UV optical lithography and reactive ion etching in a nano-photonic silicon-on-insulator (SOI) material platform. The fabricated device was then characterized in the lab. Furthermore, incorporation of the DBR structure at the facets of the conventional etched diffraction grating decouples the reflection and diffraction functionalities, rendering the DEDG suitable for spectral response engineering. According to the application, the output spectral response of the device can be tailored through careful design and optimization of the incorporated DBR. In this thesis, through numerical simulations we have shown that functionalities such as polarization independent performance and at top insertion loss envelop are viable. A methodology to engineer the spectral response of the DEDG is discussed in details.

  2. Fire in ice: two millennia of Northern Hemisphere fire history from the Greenland NEEM ice core

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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, 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.

  3. Superheater Corrosion Produced By Biomass Fuels

    SciTech Connect

    Sharp, William; Singbeil, Douglas; Keiser, James R

    2012-01-01

    About 90% of the world's bioenergy is produced by burning renewable biomass fuels. Low-cost biomass fuels such as agricultural wastes typically contain more alkali metals and chlorine than conventional fuels. Although the efficiency of a boiler's steam cycle can be increased by raising its maximum steam temperature, alkali metals and chlorine released in biofuel boilers cause accelerated corrosion and fouling at high superheater steam temperatures. Most alloys that resist high temperature corrosion protect themselves with a surface layer of Cr{sub 2}O{sub 3}. However, this Cr{sub 2}O{sub 3} can be fluxed away by reactions that form alkali chromates or volatilized as chromic acid. This paper reviews recent research on superheater corrosion mechanisms and superheater alloy performance in biomass boilers firing black liquor, biomass fuels, blends of biomass with fossil fuels and municipal waste.

  4. Curved VPH gratings for novel spectrographs

    NASA Astrophysics Data System (ADS)

    Clemens, J. Christopher; O'Donoghue, Darragh; Dunlap, Bart H.

    2014-07-01

    The introduction of volume phase holographic (VPH) gratings into astronomy over a decade ago opened new possibilities for instrument designers. In this paper we describe an extension of VPH grating technology that will have applications in astronomy and beyond: curved VPH gratings. These devices can disperse light while simultaneously correcting aberrations. We have designed and manufactured two different kinds of convex VPH grating prototypes for use in off-axis reflecting spectrographs. One type functions in transmission and the other in reflection, enabling Offnerstyle spectrographs with the high-efficiency and low-cost advantages of VPH gratings. We will discuss the design process and the tools required for modelling these gratings along with the recording layout and process steps required to fabricate them. We will present performance data for the first convex VPH grating produced for an astronomical spectrograph.

  5. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .../capacity, and is properly equipped to handle both fire fighting and flood control. (b) Each vessel must... 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...

  6. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be... 46 Shipping 1 2012-10-01 2012-10-01 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...

  7. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be... 46 Shipping 1 2011-10-01 2011-10-01 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...

  8. Fire impacts on the cryosphere

    NASA Astrophysics Data System (ADS)

    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.

  9. Biotechnology of biomass conversion

    SciTech Connect

    Wayman, M.; Parekh, S.R.

    1990-01-01

    This book covers: An introduction to biomass crops; The microbiology of fermentation processes; The production of ethanol from biomass crops, such as sugar cane and rubbers; The energy of biomass conversion; and The economics of biomass conversion.

  10. COFIRING BIOMASS WITH LIGNITE COAL

    SciTech Connect

    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.