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

DEFF Research Database (Denmark)

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

2013-01-01

-chemical processes are divided in two successive sections: drying and conversion (which includes pyrolysis, gasification and combustion). The second model is an empirical 1D approach. The two models need input data such as composition, temperature and feeding rate of biomass and primary air. Temperature, species...... to describe the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. In this work both models consider the incoming solid fuel as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is treated as a 0D system, but the thermo...... concentrations and velocity of the producer gas leaving the fuel bed provided by the two models are compared. A sensitivity analysis with respect to mass flow rate of the primary air is also performed, as well as a further comparison regarding the dependence of the producer gas properties on the initial moisture...

Numerical modelling of a straw-fired grate boiler

DEFF Research Database (Denmark)

Kær, Søren Knudsen

2004-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Rosendahl, L.

2007-02-15

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

Co-firing of coal with biomass and waste in full-scale suspension-fired boilers

Energy Technology Data Exchange (ETDEWEB)

Dam-Johansen, Kim; Frandsen, Flemming J.; Jensen, Peter A.; Jensen, Anker D. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of chemical and Biochemical Engineering

2013-07-01

The energy policy in Denmark has for many years focused on lowering the net CO{sub 2} emission from heat and power production by replacing fossil fuels by renewable resources. This has been done by developing dedicated grate-fired boilers for biomass and waste fuels but also by developing coal-based suspension-fired boilers to accept still higher fractions of biomass or waste material as fuels. This last development has been challenging of many reasons, including pre-treatment of fuels, and solving potential emission and operational problems during the simultaneous development of supercritical steam cycles with steam temperatures close to 600 C, providing power efficiencies close to 50% (Hein KRG, Sustainable energy supply and environment protection - strategies, resources and technologies. In: Gupta R, Wall T, Hupa M, Wigley F, Tillman D, Frandsen FJ (eds) Proceedings of international conference on impact of fuel quality on power production and the environment, Banff Conference Centre, Banff, Alberta, Canada, 29 Sept-4 Oct, 2008). For 25 years the CHEC (Combustion and Harmful Emission Control) Research Centre at DTU Chemical Engineering, has attained a leading role in research, supporting power producing industry, plant owners and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools. The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This chapter provides an overview of research activities, aiming at increasing biomass shares during co-firing in suspension, conducted in close collaboration with

Advanced CFD modelling of air and recycled flue gas staging in a waste wood-fired grate boiler for higher combustion efficiency and greater environmental benefits.

Science.gov (United States)

Rajh, Boštjan; Yin, Chungen; Samec, Niko; Hriberšek, Matjaž; Kokalj, Filip; Zadravec, Matej

2018-07-15

Grate-fired boilers are commonly used to burn biomass/wastes for heat and power production. In spite of the recent breakthrough in integration of advanced secondary air systems in grate boilers, grate-firing technology needs to be advanced for higher efficiency and lower emissions. In this paper, innovative staging of combustion air and recycled flue gas in a 13 MW th waste wood-fired grate boiler is comprehensively studied based on a numerical model that has been previously validated. In particular, the effects of the jet momentum, position and orientation of the combustion air and recycled flue gas streams on in-furnace mixing, combustion and pollutant emissions from the boiler are examined. It is found that the optimized air and recycled flue gas jets remarkably enhance mixing and heat transfer, result in a more uniform temperature and velocity distribution, extend the residence time of the combustibles in the hot zone and improve burnout in the boiler. Optimizing the air and recycled flue gas jet configuration can reduce carbon monoxide emission from the boiler by up to 86%, from the current 41.0 ppm to 5.7 ppm. The findings of this study can serve as useful guidelines for novel design and optimization of the combustion air supply and flue gas recycling for grate boilers of this type. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biomass co-firing for Delta Electricity

International Nuclear Information System (INIS)

Anon

2014-01-01

Electricity generator Delta Electricity has implemented a biomass co-firing program at its Vales Point power station on the Central Coast to reduce its reliance on coal and emissions of CO 2 . The program comprises two parts: direct co-firing with coal of up to 5% biomass; and development of Continuous Biomass Converter (CBC) technology with the Crucible Group to remove technology constraints and enable much higher rates of biomass co-firing. It is talking industrial scale tests. Delta increased biomass co-firing in 2013/14 to 32,000 tonnes, up from just 3,000 tonnes the previous year, and conducted biochar co-firing trials at a rate equivalent to 400,000 tonnes per annum to demonstrate the potential of CBC technology. It reduced CO 2 emissions in 2013/14 by more than 32,000 tonnes. 'Legislation and regulations define biomass as renewable,' said Delta Electricity sustainability manager Justin Flood. 'By preferring biomass over coal, the carbon in the coal is not burnt and remains locked up.' One biomass source is wood waste that would normally go to landfill, but the primary driver of Delta's recent increase in co-firing is sawmill residues. 'Previously there was a higher value market for the residues for paper pulp. However, when that market evaporated the timber industry was left with a sizable problem in terms of what to do with its residues and the loss of revenue,' said Flood. The way greenhouse gas accounting is conducted in Australia, with carbon emissions based on site activities, makes it difficult to undertake a life cycle assessment of the program. 'However, some of the international studies looking at this issue have concluded that the net carbon emissions of the biomass system are significantly lower than the coal system because of the uptake of carbon during biomass growth,' said Flood. Delta identified two challenges, sourcing the feedstock and that biomass conversion to electricity is slightly less

Grate Firing of Biomass: Measurements, Validation and Demonstration

DEFF Research Database (Denmark)

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

The worldwide concern about global warming because of the emission of CO2 and other greenhouse gases and the limited availability of fossil fuels has increased the interest in using biomass as a fuel for energy production. In Denmark, to use biomass (mainly straw) as a fuel for energy production...

GASIFICATION BASED BIOMASS CO-FIRING

Energy Technology Data Exchange (ETDEWEB)

Babul Patel; Kevin McQuigg; Robert Toerne; John Bick

2003-01-01

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

Biomass co-firing under oxy-fuel conditions

DEFF Research Database (Denmark)

Álvarez, L.; Yin, Chungen; Riaza, J.

2014-01-01

This paper presents an experimental and numerical study on co-firing olive waste (0, 10%, 20% on mass basis) with two coals in an entrained flow reactor under three oxy-fuel conditions (21%O2/79%CO2, 30%O2/70%CO2 and 35%O2/65%CO2) and air–fuel condition. Co-firing biomass with coal was found...... to have favourable synergy effects in all the cases: it significantly improves the burnout and remarkably lowers NOx emissions. The reduced peak temperatures during co-firing can also help to mitigate deposition formation in real furnaces. Co-firing CO2-neutral biomass with coals under oxy-fuel conditions...... the model can be used to aid in design and optimization of large-scale biomass co-firing under oxy-fuel conditions....

GASIFICATION BASED BIOMASS CO-FIRING - PHASE I

Energy Technology Data Exchange (ETDEWEB)

Babul Patel; Kevin McQuigg; Robert F. Toerne

2001-12-01

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

Benefits of Allothermal Biomass Gasification for Co-Firing

Energy Technology Data Exchange (ETDEWEB)

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

2012-04-15

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

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

Directory of Open Access Journals (Sweden)

Saeed Soltani

2015-01-01

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

GASIFICATION BASED BIOMASS CO-FIRING - PHASE I; SEMIANNUAL

International Nuclear Information System (INIS)

Babul Patel; Kevin McQuigg; Robert F. Toerne

2001-01-01

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

Analysis of todays best available technology for biomass fired heating plants in the interval 0.5 to 10 MW

International Nuclear Information System (INIS)

Karlsson, Mats-Lennart; Gustavsson, Lennart; Maartensson, D.; Leckner, B.

1998-01-01

The purpose of the present project has been to study today's best available technology for biomass fired heating plants in the interval 0.5 to 10 MW from an emission point of view. Emission measurements have been conducted at 21 plants of different types and sizes, i.e. one stationary fluidized bed, fourteen boilers with moving grates, four boilers with fixed grates, one pellet burner and one boiler with a gasification oven. The plants were fired with different fuels: native fuels like wood chips, bark/sawdust, grass and refined fuels like briquettes and pellets. The plants were chosen to represent the best available and/or the most common technology. The flue gases were analyzed for CO, NO x , Total Hydrocarbons (THC), methane, ethylene, acetylene, ammonia, nitrous oxide, CO 2 and O 2 . The measurements were usually made at the heat loads and operating conditions given at the time of testing. However, in a few cases measurements were made at different loads and air settings

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

DEFF Research Database (Denmark)

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

2004-01-01

modification to the motion and reaction due to their non-sphericity. The simulation results show a big difference between the two cases and indicate it is very significant to take into account the non-sphericity of biomass particles in order to model biomass combustion more accurately. Methods to improve...... of numerical modeling. The models currently used to predict solid fuel combustion rely on a spherical particle shape assumption, which may deviate a lot from reality for big biomass particles. A sphere gives a minimum in terms of the surface-area-to-volume ratio, which impacts significantly both motion...... and reaction of a particle. To better understand biomass combustion and thus improve the design for co-firing biomass in wall-fired burners, non-sphericity of biomass particles is considered. To ease comparison, two cases are numerically studied in a 10m long gas/biomass co-fired burner model. (1) The biomass...

Drivers of biomass co-firing in U.S. coal-fired power plants

Science.gov (United States)

Michael E. Goerndt; Francisco X. Aguilar; Kenneth Skog

2013-01-01

Substantial knowledge has been generated in the U.S. about the resource base for forest and other residue-derived biomass for bioenergy including co-firing in power plants. However, a lack of understanding regarding power plant-level operations and manager perceptions of drivers of biomass co-firing remains. This study gathered information from U.S. power plant...

Modeling of aerosol formation during biomass combustion in grate furnaces and comparison with measurements

NARCIS (Netherlands)

Joeller, M.; Brunner, T.; Obernberger, I.

2005-01-01

Results from mathematical modeling of aerosol formation during combustion of woody biomass fuels were compared with results from particle size distribution (PSD) measurements at a pilot-scale biomass combustion unit with moving grate and flame tube boiler. The mathematical model is a plug flow model

Co-firing biomass and fossil fuels

International Nuclear Information System (INIS)

Junge, D.C.

1991-01-01

In June 1989, the Alaska Energy Authority and the University of Alaska Anchorage published a monograph summarizing the technology of co-firing biomass and fossil fuels. The title of the 180 page monograph is 'Use of Mixed Fuels in Direct Combustion Systems'. Highlights from the monograph are presented in this paper with emphasis on the following areas: (1) Equipment design and operational experience co-firing fuels; (2) The impact of co-firing on efficiency; (3) Environmental considerations associated with co-firing; (4) Economic considerations in co-firing; and (5) Decision making criteria for co-firing

Materials Problems and Solutions in Biomass Fired Plants

DEFF Research Database (Denmark)

Larsen, Ole Hede; Montgomery, Melanie

2006-01-01

ascribed to the composition of the deposit and the metal surface temperature. In woodchip boilers, a similar corrosion rate and corrosion mechanism has on some occasions been observed. Co-firing of straw (10 and 20% energy basis) with coal has shown corrosion rates lower than those in straw-fired plants......Due to Denmark’s pledge to reduce carbon dioxide emissions, biomass is utilised increasingly as a fuel for generating energy. Extensive research and demonstration projects especially in the area of material performance for biomass fired boilers have been undertaken to make biomass a viable fuel...... resource. When straw is combusted, potassium chloride and potassium sulphate are present in ash products, which condense on superheater components. This gives rise to specific chlorine corrosion problems not previously encountered in coal-fired power plants. The type of corrosion attack can be directly...

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Residual Ash Formation during Suspension-Firing of Biomass

DEFF Research Database (Denmark)

Damø, Anne Juul; Jappe Frandsen, Flemming; Jensen, Peter Arendt

2014-01-01

Through 50+ years, high quality research has been conducted in order to characterize ash and deposit formation in utility boilers fired with coal, biomass and waste fractions. The basic mechanism of fly ash formation in suspension fired coal boilers is well described, documented and may even...... be modeled relatively precisely. Concerning fly ash formation from biomass or waste fractions, the situation is not nearly as good. Lots of data are available from campaigns where different ash fractions, including sometimes also in-situ ash, have been collected and analyzed chemically and for particle size...... distribution. Thus, there is a good flair of the chemistry of fly ash formed in plants fired with biomass or waste fractions, either alone, or in conjunction with coal. But data on dedicated studies of the physical size development of fly ash, are almost non-existing for biomasses and waste fractions...

Biomass assessment and small scale biomass fired electricity generation in the Green Triangle, Australia

International Nuclear Information System (INIS)

Rodriguez, Luis C.; May, Barrie; Herr, Alexander; O'Connell, Deborah

2011-01-01

Coal fired electricity is a major factor in Australia's greenhouse gas emissions (GHG) emissions. The country has adopted a mandatory renewable energy target (MRET) to ensure that 20% of electricity comes from renewable sources by 2020. In order to support the MRET, a market scheme of tradable Renewable Energy Certificates (RECs) has been implemented since 2001. Generators using biomass from eligible sources are able to contribute to GHG emission reduction through the substitution of coal for electricity production and are eligible to create and trade RECs. This paper quantifies the potential biomass resources available for energy generation from forestry and agriculture in the Green Triangle, one of the most promising Australian Regions for biomass production. We analyse the cost of electricity generation using direct firing of biomass, and estimate the required REC prices to make it competitive with coal fired electricity generation. Major findings suggest that more than 2.6 million tonnes of biomass are produced every year within 200 km of the regional hub of Mount Gambier and biomass fired electricity is viable using feedstock with a plant gate cost of 46 Australian Dollars (AUD) per tonne under the current REC price of 34 AUD per MWh. These findings are then discussed in the context of regional energy security and existing targets and incentives for renewable energies. -- Highlights: → We assessed the biomass production in the Green Triangle. → 2.6 million tonnes of biomass per year are produced within 200 km from Mt Gambier. → Renewable Energy Certificates makes bioenergy competitive with coal electricity. → At a REC price of 34 AUD, biomass of up to 46 AUD/tonne might be used for bionergy

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

Directory of Open Access Journals (Sweden)

Yiming eZhu

2014-02-01

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

Materials Problems and Solutions in Biomass fired plants

DEFF Research Database (Denmark)

Larsen, Ole Hede; Montgomery, Melanie

2006-01-01

be directly ascribed to the composition of the deposit and the metal surface temperature. In woodchip boilers, a similar corrosion rate and corrosion mechanism has on some occasions been observed. Cofiring of straw (10 and 20% energy basis) with coal has shown corrosion rates lower than those in straw fired......Owing to Denmark's pledge to reduce carbon dioxide emissions, biomass is being increasingly utilised as a fuel for generating energy. Extensive research and development projects, especially in the area of material performance for biomass fired boilers, have been undertaken to make biomass a viable...... fuel resource. When straw is combusted, potassium chloride and potassium sulphate are present in ash products, which condense on superheater components. This gives rise to specific chlorine corrosion problems not previously encountered in coal fired power plants. The type of corrosion attack can...

Climate change impact on landscape fire and forest biomass dynamics

International Nuclear Information System (INIS)

Li, C.

2004-01-01

The aim of this study was to improve current understandings of fire regimes. The estimation of biomass dynamics at the stand scale is essential for understanding landscape scale biomass dynamics, particularly in order to understand the potential effects of fire regimes. This study presented a synthesis of research results obtained from stand scale studies together with fire behaviour and weather variables. Landscape structure, topography and climate conditions were also considered. Integration of the data was conducted with the SEM-LAND model, a spatially explicit model for landscape dynamics. Equations for the model were presented, including fire initiation and spread, as well as a lightning fire process and simulated fire suppression. Results indicated that fire suppression could alter the distribution of fire sizes. The effect of tree and stand mortality on forest biomass estimates was also discussed along with the impact of climate change on fire regimes. Results indicate that fire activities are likely to increase. Results also demonstrate that fire frequency and size distribution are correlated without human intervention. Theoretical negative exponential forest age distribution is not always supported by empirical observations. Point-based fire frequency and fire cycle definitions are special cases from a computational perspective. Detection of quantitative interrelationships may simplify preconditions for estimating fire regimes, and serve as a means to address incomplete empirical observations. 12 refs., 3 figs

A review: Fly ash and deposit formation in PF fired biomass boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt; Jappe Frandsen, Flemming; Wu, Hao

2016-01-01

In recent years suspension fired boilers have been increasingly used for biomass based heat and power production in several countries. This has included co-firing of coal and straw, up to 100% firing of wood or straw and the use of additives to remedy problems with biomass firing. In parallel...

Norwegian wood? Biomass co-firing at Drax

Energy Technology Data Exchange (ETDEWEB)

Probert, T.

2009-11-15

PEi reports on a visit to the giant Drax coal fired power station in North Yorkshire, UK. The second largest coal plant in Europe is the site of a co-firing system that will allow for the displacement of ten per cent of its coal throughput in favour of biomass, thus reducing its sizeable carbon footprint by around two million tonnes a year. Tests on a pilot plant have shown that Drax can burn up to 60 types of biomass using existing coal burners. The majority of biomass will be imported - most likely wood from Scandinavia, The Baltics and North America. Drax would be eligible for one-half of a Renewable Obligation Certificate. Carbon dioxide emissions should be reduced by around 2 million tonnes per year. 3 photos.

The feasibility of co-firing biomass for electricity in Missouri

International Nuclear Information System (INIS)

Liu, Zuoming; Altman, Ira; Johnson, Thomas G.

2014-01-01

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

Characterization of biomass burning aerosols from forest fire in Indonesia

Science.gov (United States)

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

Emission of nitrogen oxides from small biomass-fired grate boilers - a literature survey

International Nuclear Information System (INIS)

Olsson, Daniel

1999-05-01

A literature study has been carried out to find mechanisms for control of nitrogen oxide emissions from small-scale biomass fired combustion devices. The underlying nitrogen chemistry has been studied. Three paths of nitrogen oxide formation has been identified: 1. Thermal NO x , 2, Prompt NO x , and, 3. Fuel NO x . Out of these three mechanisms only fuel NO x is of interest, and the others are neglected at the temperature level concerned. The results from this study have been used to identify limitations and possibilities for NO x and CO abatement. A beacon has been to find efficient methods for NO x abatement at the same time as complete burn-out of the fuel is of greatest importance. The NO x abatement work of many of the Swedish manufacturers of small-scale combustion devices is described. This gives valuable insight in the practical possibilities and limitations in strive for low NOx emissions. From the literature and the contacts with manufacturers some factors of great importance for NO x emission control have been identified. These are: * The fuel (nitrogen content, shape, size, the height of the fuel layer and the tendency of the fuel to stick), * The stoichiometry in the volume above the fuel bed (should be 0.6 - 0.8), * The mixing of the gases above the fuel bed, * The mixing of tertiary air into the main gas flow, and * The thermal load of the combustion chamber (residence time). All the secondary measures studied but selective catalytic reduction have been rejected. Selective catalytic reduction could be a possible solution to the NO x emission problem if it is necessary to further lower the emissions from these small-scale biomass combustion devices despite the cost Project report from the program: Small scale combustion of biofuels. 22 refs, 30 figs, 4 tabs

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

DEFF Research Database (Denmark)

Montgomery, Melanie; Larsen, OH; Biede, O

2003-01-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

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

Directory of Open Access Journals (Sweden)

Man-Keun Kim

2015-07-01

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

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

Science.gov (United States)

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.

Gas turbines: gas cleaning requirements for biomass-fired systems

OpenAIRE

Oakey, John; Simms, Nigel; Kilgallon, Paul

2004-01-01

Increased interest in the development of renewable energy technologies has been hencouraged by the introduction of legislative measures in Europe to reduce CO2 emissions from power generation in response to the potential threat of global warming. Of these technologies, biomass-firing represents a high priority because of the modest risk involved and the availability of waste biomass in many countries. Options based on farmed biomass are also under development. This paper reviews the challenge...

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-09-01

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

Biomass for electricity in the EU-27: Potential demand, CO2 abatements and breakeven prices for co-firing

International Nuclear Information System (INIS)

Bertrand, Vincent; Dequiedt, Benjamin; Le Cadre, Elodie

2014-01-01

This paper analyses the potential of biomass-based electricity in the EU-27 countries, and interactions with climate policy and the EU ETS. We estimate the potential biomass demand from the existing power plants, and we match our estimates with the potential biomass supply in Europe. Furthermore, we compute the CO2 abatement associated with the co-firing opportunities in European coal plants. We find that the biomass demand from the power sector may be very high compared with potential supply. We also identify that co-firing can produce high volumes of CO 2 abatements, which may be two times larger than that of the coal-to-gas fuel switching. We also compute biomass and CO2 breakeven prices for co-firing. Results indicate that biomass-based electricity remains profitable with high biomass prices, when the carbon price is high: a Euros 16–24 (25–35, respectively) biomass price (per MWh prim ) for a Euros 20 (50, respectively) carbon price. Hence, the carbon price appears as an important driver, which can make profitable a high share of the potential biomass demand from the power sector, even with high biomass prices. This aims to gain insights on how biomass market may be impacted by the EU ETS and others climate policies. - Highlights: • Technical potential of biomass (demand and CO 2 abatement) in European electricity. • Calculation for co-firing and biomass power plants; comparison with potential biomass supply in EU-27 countries. • Calculation of biomass and CO 2 breakeven prices for co-firing. • Potential demand is 8–148% of potential supply (up to 80% of demand from co-firing). • High potential abatement from co-firing (up to 365 Mt/yr); Profitable co-firing with €16-24 (25–35) biomass price for €20 (50) CO 2 price

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-06-01

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

Experimental analysis of a combustion reactor under co-firing coal with biomass

Energy Technology Data Exchange (ETDEWEB)

Pereira, Fabyo Luiz; Bazzo, Edson; Oliveira Junior, Amir Antonio Martins de [Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil). LabCET], e-mail: ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Complexo Termeletrico Jorge Lacerda, Capivari de Baixo, SC (Brazil)], e-mail: marcelob@tractebelenergia.com.br

2010-07-01

Mitigation of greenhouse gases emission is one of the most important issues in energy engineering. Biomass is a potential renewable source but with limited use in large scale energy production because of the relative smaller availability as compared to fossil fuels, mainly to coal. Besides, the costs concerning transportation must be well analysed to determine its economic viability. An alternative for the use of biomass as a primary source of energy is the co-firing, that is the possibility of using two or more types of fuels combined in the combustion process. Biomass can be co-fired with coal in a fraction between 10 to 25% in mass basis (or 4 to 10% in heat-input basis) without seriously impacting the heat release characteristics of most boilers. Another advantage of cofiring, besides the significant reductions in fossil CO{sub 2} emissions, is the reduced emissions of NO{sub x} and SO{sub x}. As a result, co-firing is becoming attractive for power companies worldwide. This paper presents results of some experimental analysis on co-firing coal with rice straw in a combustion reactor. The influence of biomass thermal share in ash composition is also discussed, showing that alkali and earth alkaline compounds play the most important role on the fouling and slagging behavior when co-firing. Some fusibility correlations that can assist in the elucidation of these behavior are presented and discussed, and then applied to the present study. Results show that for a biomass thermal share up to 20%, significant changes are not expected in fouling and slagging behavior of ash. (author)

Biomass and nutrient dynamics associated with slash fires in neotropical dry forests

International Nuclear Information System (INIS)

Kauffman, J.B.; Cummings, D.L.; Sanford, R.L. Jr.; Salcedo, I.H.; Sampaio, E.V.S.B.

1993-01-01

Unprecedented rates of deforestation and biomass burning in tropical dry forests are dramatically influencing biogeochemical cycles, resulting in resource depletion, declines in biodiversity, and atmospheric pollution. We quantified the effects of deforestation and varying levels of slash-fire severity on nutrient losses and redistribution in a second-growth tropical dry forest (open-quotes Caatingaclose quotes) near Serra Talhada, Pernambuco, Brazil. Total aboveground biomass prior to burning was ∼74 Mg/ha. Nitrogen and phosphorus concentrations were highest in litter, leaves attached to slash, and fine wood debris (< O.64 cm diameter). While these components comprised only 30% of the prefire aboveground biomass, they accounted for ∼60% of the aboveground pools of N and P. Three experimental fires were conducted during the 1989 burning season. Consumption was 78, 88, and 95% of the total aboveground biomass. As much as 96% of the prefire aboveground N and C pools and 56% of the prefire aboveground P pool was lost. Nitrogen losses exceeded 500 kg/ha and P losses exceeded 20 kg/ha in the fires of the greatest severity. With increasing fire severity, the concentrations of N and P in ash decreased while the concentration of Ca increased. Greater ecosystem losses of these nutrients occurred with increasing fire severity. Following fire, up to 47% of the residual aboveground N and 84% of the residual aboveground P were in the form of ash, quickly lost from the site via wind erosion. Fires appeared to have a minor immediate effect on total N, C, or P in the soils. However, soils in forests with no history of cultivation had significantly higher concentrations of C and P than second-growth forests. It would likely require a century or more of fallow for reaccumulation to occur. However, current fallow periods in this region are 15 yr or less. 38 refs., 2 figs., 7 tabs

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

International Nuclear Information System (INIS)

Van Ree, R.; Korbee, R.; Eenkhoorn, S.; De Lange, T.; Groenendaal, B.

2000-01-01

In this paper the technical, economic, and environmental potential of co-firing of biomass in existing Dutch coal and natural gas fired power plants, and industrial combined-cycles (CC), is addressed. Main criteria that are considered are: the availability and contractibility of biomass for energy purposes; the (technical) operation of the conventional fossil fuel based processes may not be disturbed; the gaseous and liquid plant emissions have to comply to those applicable for power plants/CCs, the commercial applicability of the solid residues may not be negatively influenced; applicable additional biomass conversion technologies must be commercially available; the necessary additional investment costs must be acceptable from an economic point of view, and the co-firing option must result in a substantial CO 2 -emission reduction. The main result of the study described in the paper is the presentation of a clear and founded indication of the total co-firing potential of biomass in existing power plants and industrial CCs in the Netherlands. This potential is determined by considering both technical, economic, and environmental criteria. In spite of the fact that the co-firing potential for the specific Dutch situation is presented, the results of the criteria considered are more generally applicable, and therefore are also very interesting for potential co-firing initiatives outside of the Netherlands

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

Energy Technology Data Exchange (ETDEWEB)

Agu, R.C.; Amadife, A.E.; Ude, C.M.; Onyia, A.; Ogu, E.O. [Enugu State Univ. of Science and Technology (Nigeria). Faculty of Applied Natural Sciences; Okafor, M.; Ezejiofor, E. [Nnamdi Azikiwe Univ., Awka (Nigeria). Dept. of Applied Microbiology

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.

Combustion and emission formation in a biomass fueled grate furnace - measurements and modelling

International Nuclear Information System (INIS)

Lindsjoe, H.

1997-06-01

A study of turbulent combustion with special emphasis on the formation of nitrous oxide emissions in a biomass fueled grate furnace has been conducted with the aid of measurements, literature studies and CFD-computations. The literature study covers nitrous oxide formation and the pyrolysis, gasification and combustion of biomass fuel. The measurements were conducted inside the furnace and at the outlet, and temperature and some major species were measured. A tool for the treatment of the bed processes (pyrolysis, gasification and combustion) has been developed. The measurements show significantly higher concentrations of oxygen above the fuel bed than expected. The gas production in the bed was shown to be very unevenly distributed over the width of the furnace. The measured temperatures were relatively low and in the same order as reported from other, similar measurements. The computational results are in good quantitative agreement with the measurements, even for the nitrous oxide emissions. It was necessary to include tar as one of the combustible species to achieve reasonable results. The computations point out that the fuel-NO mechanism is the most important reaction path for the formation of nitrous oxide in biomass combustion in grate furnaces. The thermal NO mechanism is responsible for less than 10% of the total amount of NO-emissions. Although the results are quantitatively in good agreement with the measurements, a sensitivity study showed that the fuel-NO model did not respond to changes in the distribution of secondary air as the measurements indicate. The results from this work have lead to some guidelines on how the furnace should be operated to achieve minimum NO-emissions. Some proposals of smaller changes in the construction are also given. 33 refs, 37 figs, 7 tabs

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-03-15

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

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

Science.gov (United States)

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

Biomass Burning Emissions from Fire Remote Sensing

Science.gov (United States)

Ichoku, Charles

2010-01-01

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

Particulate and trace gas emissions from large biomass fires in North America

International Nuclear Information System (INIS)

Radke, L.F.; Hegg, D.A.; Hobbs, P.V.; Nance, J.D.; Lyons, J.H.; Laursen, K.K.; Weiss, R.E.; Riggan, P.J.; Ward, D.E.

1991-01-01

In this chapter the authors describe the results of airborne studies of smokes from 17 biomass fuel fires, including 14 prescribed fires and 3 wildfires, burned primarily in the temperature zone of North America between 34 degree and 49 degree N latitude. The prescribed fires were in forested lands and logging debris and varied in areas burned from 10 to 700 hectares (ha) (over a few hours). One of the wildfires ultimately consumed 20,000 h a and burned over a period of weeks. The larger fires produced towering columns of smoke and capping water clouds. As an indication of scale, the prescribed fires were visible only as small features in meteorological satellite imagery, but one of the wildfires studied produced a persistent, visible plume more than 1,000 kilometers (km) long. The studies have focused on factors that could impact global climate through alteration of the earth's radiation balance. These include emissions of trace gases and smoke particles from biomass burning, the optical properties of the smoke, and the interaction of the smoke particles with clouds

Combating corrosion in biomass and waste fired plant

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

A guideline for fire prevention during the storage of biomass; Leitfaden zur Brandvermeidung bei der Lagerung von Biomasse

Energy Technology Data Exchange (ETDEWEB)

Ferrero, Fabio; Malow, Marcus; Schmidt, Martin; Krause, Ulrich

2009-10-14

For five years, an increasing number of fires in timber-yards is observed. A multiplicity of these fires results from self inflammation of the material. Under this aspect, the contribution under consideration reports on the fundamentals of the self inflammation by biomass using wood as an example. The methodology for the avoidance of the self inflammation of biomass is based on a combination of laboratory tests and numeric simulation in order to determine the reliable waste dump geometry and storage times. In particular, the humidity content of the stored material is very important for growth and heat production of the micro organisms. If the material does not possess optimal humidity content, heat production and the probability of self inflammation are reduced. The optimal content of humidity amounts nearly 50-60 mass-%. For the determination of a safe storage of biomass, a flow chart is developed using pinewood as an example. (orig.)

Global Burned Area and Biomass Burning Emissions from Small Fires

Science.gov (United States)

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

Thermal remote sensing of active vegetation fires and biomass burning events [Chapter 18

Science.gov (United States)

Martin J. Wooster; Gareth Roberts; Alistair M.S. Smith; Joshua Johnston; Patrick Freeborn; Stefania Amici; Andrew T. Hudak

2013-01-01

Thermal remote sensing is widely used in the detection, study, and management of biomass burning occurring in open vegetation fires. Such fires may be planned for land management purposes, may occur as a result of a malicious or accidental ignition by humans, or may result from lightning or other natural phenomena. Under suitable conditions, fires may spread rapidly...

Fighting fire with gas. CO{sub 2} extinguishes smouldering fires in biomass silos and waste bunkers; Effizientes Feuerwehr-Gas. CO{sub 2} loescht Schwelbraende in Biomasse-Silos und Abfallbunkern

Energy Technology Data Exchange (ETDEWEB)

Anon.

2011-07-01

Organic materials are a great source of energy and so biomass is in big demand. But wherever large amounts of wood, waste and straw are stored in huge silos, there is also a risk of smouldering fires and even explosions. Conventional methods are relatively ineffective at extinguishing fires such as these. But a new extinguishing system from Linde uses CO{sub 2} to effectively fight smouldering fires at the source. (orig.)

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

International Nuclear Information System (INIS)

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

2002-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-01-15

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

Thermo-economic assessment of externally fired micro-gas turbine fired by natural gas and biomass: Applications in Italy

International Nuclear Information System (INIS)

Pantaleo, A.M.; Camporeale, S.M.; Shah, N.

2013-01-01

Highlights: • A thermo-economic analysis of natural gas/biomass fired microturbine is proposed. • Energy efficiency, capex, opex and electricity revenues trade-offs are assessed. • The optimal biomass energy input is 70% of total CHP consumption. • Industrial/tertiary heat demand and baseload/heat driven operation is assessed. • The main barriers of small scale CHP systems in Italy are overviewed. - Abstract: This paper proposes a thermo-economic assessment of small scale (100 kWe) combined heat and power (CHP) plants fired by natural gas and solid biomass. The focus is on dual fuel gas turbine cycle, where compressed air is heated in a high temperature heat exchanger (HTHE) using the hot gases produced in a biomass furnace, before entering the gas combustion chamber. The hot air expands in the turbine and then feeds the internal pre-heater recuperator, Various biomass/natural gas energy input ratios are modeled, ranging from 100% natural gas to 100% biomass. The research assesses the trade-offs between: (i) lower energy conversion efficiency and higher investment cost of high biomass input rate and (ii) higher primary energy savings and revenues from bio-electricity feed-in tariff in case of high biomass input rate. The influence of fuel mix and biomass furnace temperature on energy conversion efficiencies, primary energy savings and profitability of investments is assessed. The scenarios of industrial vs. tertiary heat demand and baseload vs. heat driven plant operation are also compared. On the basis of the incentives available in Italy for biomass electricity and for high efficiency cogeneration (HEC), the maximum investment profitability is achieved for 70% input biomass percentage. The main barriers of these embedded cogeneration systems in Italy are also discussed

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

Directory of Open Access Journals (Sweden)

Lingling Wang

2015-02-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-05-01

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

Burning radionuclide question. What happens to iodine, cesium and chlorine in biomass fires?

International Nuclear Information System (INIS)

Amiro, B.D.; Sheppard, S.C.; Johnston, F.L.; Evenden, W.G.; Harris, D.R.

1996-01-01

Fires can mobilize radionuclides from contaminated biomass through suspension of gases and particles in the atmosphere or solubilization and enrichment of the ash. Field and laboratory burns were conducted to determine the fate of I, Cs and Cl in biomass fires. Straw, wood, peat, dulse (seaweed) and radish plants were combusted with temperatures varying from 160 to 1000C, representing the normal range of field fire temperatures. Loss to the atmosphere increased with fire temperature and during a typical field fire, 80 - 90% of the I and Cl, and 40 - 70% of the Cs was lost to the atmosphere. The remainder was left behind in the ash and was soluble. Typically, the ash was enriched in I by a factor of two to three, with higher enrichments of Cs and lower enrichments of Cl, when compared to the initial fuel concentration during field burns. Most of the I was lost to the atmosphere as a gas. If the elements were radioactive isotopes, such as 129 I, 137 Cs and 36 Cl, fires could cause an increased radiological dose to people through inhalation, exposure to ash, or ingestion of plants because of increased uptake of ash leachate

Danish Experiences with Deposit Probe Measurements in Grate and Pulverized Fuel Biomass Power Boilers

DEFF Research Database (Denmark)

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

2012-01-01

Several measuring campaigns with focus on deposition behavior have been conducted at full-scale power plants firing biomass in Denmark. These campaigns have been reviewed in this work. The focus is the obtained experiences on deposit formation, shedding and chemistry. When comparing results from...

Optimal Level of Woody Biomass Co-Firing with Coal Power Plant Considering Advanced Feedstock Logistics System

Directory of Open Access Journals (Sweden)

Sangpil Ko

2018-05-01

Full Text Available Co-firing from woody biomass feedstock is one of the alternatives toward increased use of renewable feedstock in existing coal power plants. However, the economic level of co-firing at a particular power plant depends on several site-specific factors. Torrefaction has been identified recently as a promising biomass pretreatment option to lead to reduction of the feedstock delivered cost, and thus facilitate an increase in the co-firing ratio. In this study, a mixed integer linear program (MILP is developed to integrate supply chain of co-firing and torrefaction process and find the optimal level of biomass co-firing in terms of minimized transportation and logistics costs, with or without tax credits. A case study of 26 existing coal power plants in three Great Lakes States of the US is used to test the model. The results reveal that torrefaction process can lead to higher levels of co-firing, but without the tax credit, the effect is limited to the low capacity of power plants. The sensitivity analysis shows that co-firing ratio has higher sensitivity to variation in capital and operation costs of torrefaction than to the variation in the transportation and feedstock purchase costs.

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-08-28

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

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

Energy Technology Data Exchange (ETDEWEB)

Frandsen, Flemming J.; Lith, S. van

2009-10-15

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

International Nuclear Information System (INIS)

McLaughlin, H.

2009-01-01

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

Permitting a biomass-fired power plant in California -- A case study

International Nuclear Information System (INIS)

Reisman, J.I.; Needham, G.A.

1995-01-01

This paper describes the process of preparing an air permit application for a proposed biomass-fired power plant. The plant is designed to produce a net electric power output of 16 megawatts (MW) for sale to Pacific Gas and Electric Company. The biomass fuel will consist of urban wood waste, construction wood waste, and waste from agricultural products, such as tree prunings and fruit pits. The site is located in an industrial park in Soledad, California

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

Science.gov (United States)

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

2016-06-01

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

Co-firing of biomass and other wastes in fluidised bed systems

Energy Technology Data Exchange (ETDEWEB)

Gulyurtlu, I.; Lopes, H.; Boavida, D.; Abelha, P. [INETI/DEECA, Lisboa (Portugal); Werther, J.; Hartge, E.-U.; Wischnewski, R. [TU Hamburg-Harburg (Georgia); Leckner, B.; Amand, L.-E.; Davidsson, K. [Chalmers Univ. of Technology (Sweden); Salatino, P.; Chirone, R.; Scala, F.; Urciuolo, M. [Dipartimento di Ingegneria Chimica, Universita di Napoli Frederico II and Istituto di Ricerche sulla Combustione (Italy); Oliveira, J.F.; Lapa, N.

2006-07-01

A project on co-firing in large-scale power plants burning coal is currently funded by the European Commission. It is called COPOWER. The project involves 10 organisations from 6 countries. The project involves combustion studies over the full spectrum of equipment size, ranging from small laboratory-scale reactors and pilot plants, to investigate fundamentals and operating parameters, to proving trials on a commercial power plant in Duisburg. The power plant uses a circulating fluidized bed boiler. The results to be obtained are to be compared as function of scale-up. There are two different coals, 3 types of biomass and 2 kinds of waste materials are to be used for blending with coal for co-firing tests. The baseline values are obtained during a campaign of one month at the power station and the results are used for comparison with those to be obtained in other units of various sizes. Future tests will be implemented with the objective to achieve improvement on baseline values. The fuels to be used are already characterized. There are ongoing studies to determine reactivities of fuels and chars produced from the fuels. Reactivities are determined not only for individual fuels but also for blends to be used. Presently pilot-scale combustion tests are also undertaken to study the effect of blending coal with different types of biomass and waste materials. The potential for synergy to improve combustion is investigated. Simultaneously, studies to verify the availability of biomass and waste materials in Portugal, Turkey and Italy have been undertaken. Techno-economic barriers for the future use of biomass and other waste materials are identified. The potential of using these materials in coal fired power stations has been assessed. The conclusions will also be reported.

Gas turbines: gas cleaning requirements for biomass-fired systems

Directory of Open Access Journals (Sweden)

Oakey John

2004-01-01

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

Cocombustion of biomass in coal-fired power plants; Meestoken van biomassa in kolengestookte E-centrales

Energy Technology Data Exchange (ETDEWEB)

Albrink, W.G.M. [Stork Thermeq, Hengelo (Netherlands)

2001-12-01

The aim of the desk study is to determine to what degree several types of biomass can be cofired with existing coal fired utility boilers in the Netherlands. All results with regard to boiler performances are obtained by making use of a computer model of a typical coal fired boiler which make part of a 600 MWe coal fired power plant. Because the existing coal fired units in the Netherlands do deviate more or less from the used model all outcomes and conclusions of this study are indicative. Slagging and corrosion which become more important when firing biogas in a coal fired boiler are considered superficially. More close investigations are necessary when carry out concrete projects. Furthermore all results are based on 100% boiler load and may not be used or extrapolated to part load conditions. The extent of firing biomass gas may depend on available space in the boiler house and correlated restrictions for necessary constructive adaptations. These aspects were leave out of consideration. For information the necessary size of piping for biomass gas from gasifier to the boiler has been determined for several amounts of biomass. [Dutch] Het doel van de studie is te onderzoeken hoeveel biomassa, in percentage van het thermisch vermogen, volgens verschillende concepten kan worden meegestookt in een kolengestookte elektriciteitscentrale. Dit wordt in deze studie behandeld aan de hand van een aantal aspecten: Rookgashoeveelheden door de ketel. Hierbij kornen de volgende zaken aan de orde: snelheden, drukval, belasting van DeNox, DeSox en E-filters, capaciteit van de ventilatoren; Rookgastemperaturen. Dit betreft temperaturen uitlaat vuurhaard, uitlaat ketel en uitlaat LUVO (luchtverhitter); Verslakking en corrosie van oververhitters; Water/stoomzijdige flows. Dit betreft aspecten als flows, temperaturen, flow door de turbine (slikvermogen) en uitlaatconditie stoomturbine (vochtgehalte). Voor de verwerking van biomassa worden alleen vergassing (in hoofdzaak) en, minder

The Use of Fire Radiative Power to Estimate the Biomass Consumption Coefficient for Temperate Grasslands in the Atlantic Forest Biome

Directory of Open Access Journals (Sweden)

Bibiana Salvador Cabral da Costa

Full Text Available Abstract Every year, many active fire spots are identified in the satellite images of the southern Brazilian grasslands in the Atlantic Forest biome and Pampa biome. Fire Radiative Power (FRP is a technique that uses remotely sensed data to quantify burned biomass. FRP measures the radiant energy released per time unit by burning vegetation. This study aims to use satellite and field data to estimate the biomass consumption rate and the biomass consumption coefficient for the southern Brazilian grasslands. Three fire points were identified in satellite FRP products. These data were combined with field data, collected through literature review, to calculate the biomass consumption coefficient. The type of vegetation is an important variable in the estimation of the biomass consumption coefficient. The biomass consumption rate was estimated to be 2.237 kg s-1 for the southern Brazilian grasslands in Atlantic Forest biome, and the biomass consumption coefficient was estimated to be 0.242 kg MJ-1.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-01-15

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

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

DEFF Research Database (Denmark)

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

2017-01-01

Superheater tubes in biomass-fired power plants experience high corrosion rates due to condensation of corrosive alkali chloride-rich deposits. To explore the possibility of reducing the corrosion attack by the formation of an initial protective oxide layer, the corrosion resistance of pre......-oxidised Al and Ti-containing alloys (Kanthal APM and Nimonic 80A, respectively) was investigated under laboratory conditions mimicking biomass firing. The alloys were pre-oxidised at 900°C for 1 week. Afterwards, pre-oxidised samples, and virgin non-pre-oxidised samples as reference, were coated...... with a synthetic deposit of KCl and exposed at 560°C for 1 week to a gas mixture typical of biomass firing. Results show that pre-oxidation could hinder the corrosion attack; however, the relative success was different for the two alloys. While corrosion attack was observed on the pre-oxidised Kanthal APM, the pre...

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

Directory of Open Access Journals (Sweden)

G. Pereira

2016-06-01

Full Text Available 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

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

International Nuclear Information System (INIS)

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

2015-01-01

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. (letter)

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-01

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

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

DEFF Research Database (Denmark)

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

2007-01-01

Over the past years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore to combat chloride corrosion problems co-firing of biomass with a fossil fuel has been undertaken....... This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other corrosion mechanisms...... appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 hours using 0-20% straw co-firing with coal, the plant now runs with a fuel of 10% straw + coal. After three years exposure in this environment...

Computational fluid dynamics (CFD) modelling of coal/biomass co-firing in pulverised fuel boilers

Energy Technology Data Exchange (ETDEWEB)

Moghtaderi, B.; Meesri, C. [University of Newcastle, Callaghan, NSW (Australia). CRC for Coal in Sustainable Development, Dept. of Chemical Engineering

2002-07-01

The present study is concerned with computational fluid dynamics (CFD) modelling of coal/biomass blends co-fired under conditions pertinent to pulverised fuel (PF) boilers. The attention is particularly focused on the near burner zone to examine the impact of biomass on the flame geometry and temperature. The predictions are obtained by numerical solution of the conservation equations for the gas and particle phases. The gas phase is solved in the Eulerian domain using steady-state time-averaged Navier-Stokes equations while the solution of the particle phase is obtained from a series of Lagrangian particle tracking equations. Turbulence is modelled using the {kappa}-{epsilon} and Reynolds Stress models. The comparison between the predictions and experimental measurement reported in the literature resulted in a good agreement. Other influences of biomass co-firing are observed for fuel devolatilisation and burnout. 19 refs., 6 figs.

Energy production from biomass

International Nuclear Information System (INIS)

Bestebroer, S.I.

1995-01-01

The aim of the task group 'Energy Production from Biomass', initiated by the Dutch Ministry of Economic Affairs, was to identify bottlenecks in the development of biomass for energy production. The bottlenecks were identified by means of a process analysis of clean biomass fuels to the production of electricity and/or heat. The subjects in the process analysis are the potential availability of biomass, logistics, processing techniques, energy use, environmental effects, economic impact, and stimulation measures. Three categories of biomass are distinguished: organic residual matter, imported biomass, and energy crops, cultivated in the Netherlands. With regard to the processing techniques attention is paid to co-firing of clean biomass in existing electric power plants (co-firing in a coal-fired power plant or co-firing of fuel gas from biomass in a coal-fired or natural gas-fired power plant), and the combustion or gasification of clean biomass in special stand-alone installations. 5 figs., 13 tabs., 28 refs

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

International Nuclear Information System (INIS)

Arumugam, S.; Thien, B.; Annamalai, K.; Sweeten, J.

2005-01-01

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

Estimating root biomass and distribution after fire in a Great Basin woodland using cores and pits

Science.gov (United States)

Benjamin M. Rau; Dale W. Johnson; Jeanne C. Chambers; Robert R. Blank; Annmarie Lucchesi

2009-01-01

Quantifying root biomass is critical to an estimation and understanding of ecosystem net primary production, biomass partitioning, and belowground competition. We compared 2 methods for determining root biomass: a new soil-coring technique and traditional excavation of quantitative pits. We conducted the study in an existing Joint Fire Sciences demonstration area in...

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

Science.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-06-01

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

Resource potential for renewable energy generation from co-firing of woody biomass with coal in the Northern U.S.

Science.gov (United States)

Michael E. Goerndt; Francisco X. Aguilar; Kenneth Skog

2013-01-01

Past studies have established measures of co-firing potential at varying spatial scales to assess opportunities for renewable energy generation from woody biomass. This study estimated physical availability, within ecological and public policy constraints, and associated harvesting and delivery costs of woody biomass for co-firing in selected power plants of the...

Thermal Pretreatment of Wood for Co-gasification/co-firing of Biomass and Coal

Energy Technology Data Exchange (ETDEWEB)

Wang, Ping [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Howard, Bret [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hedges, Sheila [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Morreale, Bryan [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Van Essendelft, Dirk [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Berry, David [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

2013-10-29

Utilization of biomass as a co-feed in coal and biomass co-firing and co-gasification requires size reduction of the biomass. Reducing biomass to below 0.2 mm without pretreatment is difficult and costly because biomass is fibrous and compressible. Torrefaction is a promising thermal pretreatment process and has the advantages of increasing energy density, improving grindability, producing fuels with more homogenous compositions and hydrophobic behavior. Temperature is the most important factor for the torrefaction process. Biomass grindability is related to cell wall structure, thickness and composition. Thermal treatment such as torrefaction can cause chemical changes that significantly affect the strength of biomass. The objectives of this study are to understand the mechanism by which torrefaction improves the grindability of biomass and discuss suitable temperatures for thermal pretreatment for co-gasification/co-firing of biomass and coal. Wild cherry wood was selected as the model for this study. Samples were prepared by sawing a single tangential section from the heartwood and cutting it into eleven pieces. The samples were consecutively heated at 220, 260, 300, 350, 450 and 550⁰C for 0.5 hr under flowing nitrogen in a tube furnace. Untreated and treated samples were characterized for physical properties (color, dimensions and weight), microstructural changes by SEM, and cell wall composition changes and thermal behaviors by TGA and DSC. The morphology of the wood remained intact through the treatment range but the cell walls were thinner. Thermal treatments were observed to decompose the cell wall components. Hemicellulose decomposed over the range of ~200 to 300⁰C and resulted in weakening of the cell walls and subsequently improved grindability. Furthermore, wood samples treated above 300⁰C lost more than 39% in mass. Therefore, thermal pretreatment above the hemicelluloses decomposition temperature but below 300⁰C is probably sufficient to

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

DEFF Research Database (Denmark)

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

2007-01-01

A sample of 1.2 kg Danish wheat straw (Jutland, 1997) prepared for suspension firing in a PF boiler has been analyzed for the purpose of generating size and shape distribution functions applicable to numerical modelling of combustion processes involving biomass, characterised by highly anisotropic...... shapes. The sample is subdivided by straw type, and coherent size, type and mass distribution parameters are reported for the entire sample. This type of data is necessary in order to use CFD reliably as a design and retrofit tool for co-firing biomass with fossil fuels, as the combustion processes...

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-01-15

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

Characteristics of smoke emissions from biomass fires of the Amazon region--Base-A experiment

International Nuclear Information System (INIS)

Ward, D.E.; Setzer, A.W.; Kaufman, Y.J.; Rasmussen, R.A.

1991-01-01

An airborne sampling system was used to collect grab samples of smokes for analysis of both in-plume smoke characteristics and ambient air in Brazil. In addition to the emission measurements, the chemical composition of the forest biomass burned by one fire in the Amazon region of Brazil was compared to the fuel composition for biomass burned in North America. The limited data set suggests that combustion efficiencies for tropical biomass combustion are higher than those of temperature forest fuels, as are emission factors for carbon dioxide

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

Energy Technology Data Exchange (ETDEWEB)

Hjerrild Zeuthen, J

2007-05-15

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

Experimental investigation of combustion of biomass slurry in an oil fired furnace

Energy Technology Data Exchange (ETDEWEB)

Prakash, S.V. [Mechanical Dept., M.S. Ramaiah Inst. of Tech., Bangalore (India); Shankapal, S.R. [M.S. Ramaiah School of Advanced Studies, Bangalore (India)

2008-07-01

An experimental investigation of combustion of biomass slurry in an oil fired furnace was carried out using pulverized coconut shell (CSP), LDO and water. The effect of equivalence ratio on the slurry composition, calorific value and the effect of exhaust gas percentage are presented. The calorific value of the biomass slurry increases with equivalence ratio initially, attains a peak value and then decreases with the increase in equivalence ratio. It is also observed that with the increase in composition of biomass slurry, the cost of the fuel and the percentage emission of CO decreases. It was found that CSP up to a blend of 20% was more convenient to be used as a slurry fuel in the furnace. (orig.)

Retrofit options to enable biomass firing at Irish peat plants: Background report 4.2 for the EU Joule 2+ project: Energy from biomass: An assessment of two promising systems for energy production

International Nuclear Information System (INIS)

Van den Broek, R.; Faaij, A.; Blaney, G.

1995-05-01

An overview is given of the most promising options for retrofitting existing Irish peat plants to accept biomass fuel. It is expected that with low investment costs the existing peat stations can be adapted to enable them to fire biomass. It will also be possible to co-fire peat and biomass, this option will become a way of using biomass in power generation with relatively low risk, both on the field of initial investments and supply security. The objectives of this report are: assessing the different technical options for retrofitting the plants to enable biomass firing; provide investment costs, efficiencies, emissions and expected lifetimes for the different retrofit options. The results from this study are used in the final integration phase of the EU-Joule project 'Energy from biomass'. Chapter 2 deals with methodological considerations which have been made in estimation of the investment costs. In chapter 3 the present situation is described. Both peat harvesting and power plant operation of both sod and milled peat plants are explained. Also some past experiences with wood chips firing in Irish peat stations are discussed. Chapter 4 gives a general view on retrofitting peat plants to enable biomass firing. Some starting points like biomass fuel feeding and emission standards that have to be met are highlighted. The rationale behind four main choices are given. Finally, a technical description is presented of the two boiler adaptations that will be considered among the different retrofit options, namely conversion of milled peat units into bubbling fluidized bed and into a whole tree energy unit. Six retrofit options are described in more detail in chapter 5. Information is given on the present status of the plants, the technical considerations of the retrofit, expected performance and an estimation of a range in which the investment costs can be expected. 4 figs., 10 tabs., 5 appendices

[Simulating the effects of climate change and fire disturbance on aboveground biomass of boreal forests in the Great Xing'an Mountains, Northeast China].

Science.gov (United States)

Luo, Xu; Wang, Yu Li; Zhang, Jin Quan

2018-03-01

Predicting the effects of climate warming and fire disturbance on forest aboveground biomass is a central task of studies in terrestrial ecosystem carbon cycle. The alteration of temperature, precipitation, and disturbance regimes induced by climate warming will affect the carbon dynamics of forest ecosystem. Boreal forest is an important forest type in China, the responses of which to climate warming and fire disturbance are increasingly obvious. In this study, we used a forest landscape model LANDIS PRO to simulate the effects of climate change on aboveground biomass of boreal forests in the Great Xing'an Mountains, and compared direct effects of climate warming and the effects of climate warming-induced fires on forest aboveground biomass. The results showed that the aboveground biomass in this area increased under climate warming scenarios and fire disturbance scenarios with increased intensity. Under the current climate and fire regime scenario, the aboveground biomass in this area was (97.14±5.78) t·hm -2 , and the value would increase up to (97.93±5.83) t·hm -2 under the B1F2 scenario. Under the A2F3 scenario, aboveground biomass at landscape scale was relatively higher at the simulated periods of year 100-150 and year 150-200, and the value were (100.02±3.76) t·hm -2 and (110.56±4.08) t·hm -2 , respectively. Compared to the current fire regime scenario, the predicted biomass at landscape scale was increased by (0.56±1.45) t·hm -2 under the CF2 scenario (fire intensity increased by 30%) at some simulated periods, and the aboveground biomass was reduced by (7.39±1.79) t·hm -2 in CF3 scenario (fire intensity increased by 230%) at the entire simulation period. There were significantly different responses between coniferous and broadleaved species under future climate warming scenarios, in that the simulated biomass for both Larix gmelinii and Betula platyphylla showed decreasing trend with climate change, whereas the simulated biomass for Pinus

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

Directory of Open Access Journals (Sweden)

W. Michael Griffin

2014-02-01

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

Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

Science.gov (United States)

T. G. Soares Neto; J. A. Carvalho; C. A. G. Veras; E. C. Alvarado; R. Gielow; E. N. Lincoln; T. J. Christian; R. J. Yokelson; J. C. Santos

2009-01-01

Biomass consumption and CO2, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48% and the estimated average moisture content of fresh biomass was 42% on...

ALTENER - Biomass event in Finland

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

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

ALTENER - Biomass event in Finland

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

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

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

DEFF Research Database (Denmark)

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

2015-01-01

One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed to the fo......One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed......, [1–3]). However, complete understanding of the corrosion mechanism under biomass-firing conditions has not yet been achieved. This is attributed partly to the complex nature of the corrosion process since there are many species produced from fuel combustion which can interact with one another...... and the steel surface. Many studies have focused on specific parameters such as, deposit composition (KCl, K2SO4, K2CO3, etc.) or gas species such as HCl, SO2, H2O [4–6], however, more research is necessary to understand the interaction of deposits and gas mixtures with each other and metallic superheater...

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

Energy Technology Data Exchange (ETDEWEB)

Petrov, Miroslav P.

2002-02-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-09-15

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

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

International Nuclear Information System (INIS)

Haykiri-Acma, H.; Yaman, S.

2009-01-01

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

Sulphur capture by co-firing sulphur containing fuels with biomass fuels - optimization

International Nuclear Information System (INIS)

Nordin, A.

1992-12-01

Previous results concerning co-firing of high sulphur fuels with biomass fuels have shown that a significant part of the sulphur can be absorbed in the ash by formation of harmless sulphates. The aim of this work has been to (i) determine the maximum reduction that can be obtained in a bench scaled fluidized bed (5 kW); (ii) determine which operating conditions will give maximum reduction; (iii) point out the importance and applicability of experimental designs and multivariate methods when optimizing combustion processes; (iv) determine if the degree of sulphur capture can be correlated to the degree of slagging, fouling or bed sintering; and (v) determine if further studies are desired. The following are some of the more important results obtained: - By co-firing peat with biomass, a total sulphur retention of 70 % can be obtained. By co-firing coal with energy-grass, the total SO 2 emissions can be reduced by 90 %. - Fuel feeding rate, amount of combustion air and the primary air ratio were the most important operating parameters for the reduction. Bed temperature and oxygen level seem to be the crucial physical parameters. - The NO emissions also decreased by the sulphur reducing measures. The CO emissions were relatively high (130 mg/MJ) compared to large scale facilities due to the small reactor and the small fluctuations in the fuel feeding rate. The SO 2 emissions could however be reduced without any increase in CO emissions. - When the reactor was fired with a grass, the bed sintered at a low temperature ( 2 SO 4 and KCl are formed no sintering problems were observed. (27 refs., 41 figs., 9 tabs., 3 appendices)

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

Science.gov (United States)

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

2009-02-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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/m 3 . 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.

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

DEFF Research Database (Denmark)

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

2014-01-01

) were coated with KCl and is o-thermally exposed at 560 o C for 168 h under a flue gas corresponding to straw firing. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) characterization techniques were employed for comprehensive characterization......Both cross-sectional and plan view, ‘top-down’ characterization methods were employed , for a depth-resolved characterization of corrosion products resulting from high temperature corrosion under laboratory conditions simulating biomass firing. Samples of an austenitic stainless steel (TP 347H FG...... of the corrosion product. Results from this comprehensive characterization revealed more details on the morphology and composition of the corrosion product....

Modeling and performance analysis of CCHP (combined cooling, heating and power) system based on co-firing of natural gas and biomass gasification gas

International Nuclear Information System (INIS)

Wang, Jiangjiang; Mao, Tianzhi; Sui, Jun; Jin, Hongguang

2015-01-01

Co-firing biomass and fossil energy is a cost-effective and reliable way to use renewable energy and offer advantages in flexibility, conversion efficiency and commercial possibility. This study proposes a co-fired CCHP (combined cooling, heating and power) system based on natural gas and biomass gasification gas that contains a down-draft gasifier, ICE (internal combustion engine), absorption chiller and heat exchangers. Thermodynamic models are constructed based on a modifying gasification thermochemical equilibrium model and co-fired ICE model for electricity and heat recovery. The performance analysis for the volumetric mixture ratio of natural gas and product gas indicates that the energy and exergy efficiencies are improved by 9.5% and 13.7%, respectively, for an increasing mixture ratio of 0–1.0. Furthermore, the costs of multi-products, including electricity, chilled water and hot water, based on exergoeconomic analysis are analyzed and discussed based on the influences of the mixture ratio of the two gas fuels, investment cost and biomass cost. - Highlights: • Propose a co-fired CCHP system by natural gas and biomass gasification gas. • Modify biomass gasification and co-fired ICE models. • Present the thermodynamic analysis of the volumetric mixture ratios of two gas fuels. • Energy and exergy efficiencies are improved 9.5% and 13.7%. • Discuss multi-products’ costs influenced by investment and fuel costs.

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

DEFF Research Database (Denmark)

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

2008-01-01

Over the past few years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore, to combat chloride corrosion problems cofiring of biomass with a fossil fuel has been...... undertaken. This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other...... corrosion mechanisms appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 h using 0–20% straw co-firing with coal, the plant now runs with a fuel mix of 10% strawþcoal. Based on results from a 3 years exposure...

Biomass CCS study

Energy Technology Data Exchange (ETDEWEB)

Cavezzali, S.

2009-11-15

The use of biomass in power generation is one of the important ways in reducing greenhouse gas emissions. Specifically, the cofiring of biomass with coal could be regarded as a common feature to any new build power plant if a sustainable supply of biomass fuel is readily accessible. IEA GHG has undertaken a techno-economic evaluation of the use of biomass in biomass fired and co-fired power generation, using post-combustion capture technology. This report is the result of the study undertaken by Foster Wheeler Italiana.

Emission and properties of NO{sub x} generated during coal grate-fired in O{sub 2}/N{sub 2}/CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Xu, Li; Gao, Jian-min; Zhao, Lai-fu; Zhao, Guang-bo; Wu, Shaohua [Harbin Institute of Technology, Harbin (China). Combustion Engineering Research Inst.

2013-07-01

With the improvement of environmental protection requirements, the problems of NO{sub x} emission from industrial boiler become more and more notable. Flue gas recirculation is a low-NO{sub x} combustion technology. It draws out a part of the flue gas from rear flue and forces it into boiler. So the flue gas can serve the combustion or flow field integration. The drawn flue gas can be forced into the boiler directly, or mixed with the primary air or secondary air. To explore a real effective method of low NO{sub x} combustion, the article discusses the influence of flue gas recirculation on the formation of NO{sub x} in the process of coal grate-fired, in the way of using the unit-boiler, measuring the temperature of coal surface and composition and other important influential parameters. Experimental studies show that under the condition of grate-fired, taking Flue gas recirculation in main combustion zone, coke combustion zone and burn-out zone could notably diminish the amount of NO. And with the promotion of flue gas recirculation rate, the effect can be more noticeable.

Biomass energy conversion: conventional and advanced technologies

Energy Technology Data Exchange (ETDEWEB)

Young, B C; Hauserman, W B [Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND (United States)

1995-12-01

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

Biomass energy conversion: conventional and advanced technologies

International Nuclear Information System (INIS)

Young, B.C.; Hauserman, W.B.

1995-01-01

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

The use of remotely-sensed wildland fire radiation to infer the fates of carbon during biomass combustion - the need to understand and quantify a fire's mass and energy budget

Science.gov (United States)

Dickinson, M. B.; Dietenberger, M.; Ellicott, E. A.; Hardy, C.; Hudak, A. T.; Kremens, R.; Mathews, W.; Schroeder, W.; Smith, A. M.; Strand, E. K.

2016-12-01

Few measurement techniques offer broad-scale insight on the extent and characteristics of biomass combustion during wildland fires. Remotely-sensed radiation is one of these techniques but its measurement suffers from several limitations and, when quantified, its use to derive variables of real interest depends on an understanding of the fire's mass and energy budget. In this talk, we will review certain assumptions of wildland fire radiation measurement and explore the use of those measurements to infer the fates of biomass and the dissipation of combustion energy. Recent measurements show that the perspective of the sensor (nadir vs oblique) matters relative to estimates of fire radiated power. Other considerations for producing accurate estimates of fire radiation from remote sensing include obscuration by an intervening forest canopy and to what extent measurements that are based on the assumption of graybody/blackbody behavior underestimate fire radiation. Fire radiation measurements are generally a means of quantifying other variables and are often not of interest in and of themselves. Use of fire radiation measurements as a means of inference currently relies on correlations with variables of interest such as biomass consumption and sensible and latent heat and emissions fluxes. Radiation is an imperfect basis for these correlations in that it accounts for a minority of combustion energy ( 15-30%) and is not a constant as is often assumed. Measurements suggest that fire convective energy accounts for the majority of combustion energy and (after radiation) is followed by latent energy, soil heating, and pyrolysis energy, more or less in that order. Combustion energy in and of itself is not its potential maximum, but is reduced to an effective heat of combustion by combustion inefficiency and by work done to pyrolyze fuel (important in char production) and in moisture vaporization. The effective heat of combustion is often on the order of 65% of its potential

Renew, reduce or become more efficient? The climate contribution of biomass co-combustion in a coal-fired power plant

NARCIS (Netherlands)

Miedema, Jan H.; Benders, Rene M. J.; Moll, Henri C.; Pierie, Frank

2017-01-01

Within this paper, biomass supply chains, with different shares of biomass co-combustion in coal fired power plants, are analysed on energy efficiency, energy consumption, renewable energy production, and greenhouse gas (GHG) emissions and compared with the performance of a 100% coal supply chain

Advanced circulating fluidised bed technology (CFB) for large-scale solid biomass fuel firing power plants

Energy Technology Data Exchange (ETDEWEB)

Jaentti, Timo; Zabetta, Edgardo Coda; Nuortimo, Kalle [Foster Wheeler Energia Oy, Varkaus (Finland)

2013-04-01

Worldwide the nations are taking initiatives to counteract global warming by reducing their greenhouse gas emissions. Efforts to increase boiler efficiency and the use of biomass and other solid renewable fuels are well in line with these objectives. Circulating fluidised bed boilers (CFB) are ideal for efficient power generation, capable to fire a broad variety of solid biomass fuels from small CHP plants to large utility power plants. Relevant boiler references in commercial operation are made for Finland and Poland.

Hygroscopic behaviour of aerosol particles emitted from biomass fired grate boilers

Energy Technology Data Exchange (ETDEWEB)

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

2005-02-01

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

Hygroscopic behaviour of aerosol particles emitted from biomass fired grate boilers

International Nuclear Information System (INIS)

Rissler, Jenny; Swietlicki, Erik; Pagels, Joakim; Wierzbicka, Aneta; Bohgard, Mats; Strand, Michael; Lillieblad, Lena; Sanati, Mehri

2005-01-01

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

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

1996-01-01

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

Effects of Different Fuel Specifications and Operation Conditions on the Performance of Coated and Uncoated Superheater Tubes in Two Different Biomass-Fired Boilers

DEFF Research Database (Denmark)

Wu, Duoli; Dahl, Kristian V.; Madsen, Jesper L.

2018-01-01

Fireside corrosionis a serious concern in biomass firing powerplants such that the efficiency of boilers is limited by high temperature corrosion. Application of protective coatings on superheater tubes is a possible solution to combat fireside corrosion. The current study investigates the corros......Fireside corrosionis a serious concern in biomass firing powerplants such that the efficiency of boilers is limited by high temperature corrosion. Application of protective coatings on superheater tubes is a possible solution to combat fireside corrosion. The current study investigates...... the corrosion performance of coated tubes compared to uncoated Esshete 1250 and TP347H tubes, which were exposed in two different biomass-fired boilers for one year. Data on the fuel used, temperature of the boilers, and temperature fluctuations are compared for the two boilers, and how these factors influence...... deposit formation, corrosion, and the stability of the coatings is discussed. The coatings (Ni and Ni2Al3) showed protective behavior ina wood-fired plant where the outlet steam temperature was 520 °C. However, at the plant that fired straw with an outlet steam temperature of 540 °C and where severe...

Quantifying biomass consumption and carbon release from the California Rim fire by integrating airborne LiDAR and Landsat OLI data.

Science.gov (United States)

Garcia, Mariano; Saatchi, Sassan; Casas, Angeles; Koltunov, Alexander; Ustin, Susan; Ramirez, Carlos; Garcia-Gutierrez, Jorge; Balzter, Heiko

2017-02-01

Quantifying biomass consumption and carbon release is critical to understanding the role of fires in the carbon cycle and air quality. We present a methodology to estimate the biomass consumed and the carbon released by the California Rim fire by integrating postfire airborne LiDAR and multitemporal Landsat Operational Land Imager (OLI) imagery. First, a support vector regression (SVR) model was trained to estimate the aboveground biomass (AGB) from LiDAR-derived metrics over the unburned area. The selected model estimated AGB with an R 2 of 0.82 and RMSE of 59.98 Mg/ha. Second, LiDAR-based biomass estimates were extrapolated to the entire area before and after the fire, using Landsat OLI reflectance bands, Normalized Difference Infrared Index, and the elevation derived from LiDAR data. The extrapolation was performed using SVR models that resulted in R 2 of 0.73 and 0.79 and RMSE of 87.18 (Mg/ha) and 75.43 (Mg/ha) for the postfire and prefire images, respectively. After removing bias from the AGB extrapolations using a linear relationship between estimated and observed values, we estimated the biomass consumption from postfire LiDAR and prefire Landsat maps to be 6.58 ± 0.03 Tg (10 12  g), which translate into 12.06 ± 0.06 Tg CO2 e released to the atmosphere, equivalent to the annual emissions of 2.57 million cars.

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

Science.gov (United States)

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

2014-12-01

The potential use of microalgal biomass as a biofuel source has raised broad interest. Highly effective and economically feasible biomass generating techniques are essential to realize such potential. Flue gas from coal-fired power plants may serve as an inexpensive carbon source for microalgal culture, and it may also facilitate improvement of the environment once the gas is fixed in biomass. In this study, three strains of the genus Nannochloropsis (4-38, KA2 and 75B1) survived this type of culture and bloomed using flue gas from coal-fired power plants in 8000-L open raceway ponds. Lower temperatures and solar irradiation reduced the biomass yield and lipid productivities of these strains. Strain 4-38 performed better than the other two as it contained higher amounts of triacylglycerols and fatty acids, which are used for biodiesel production. Further optimization of the application of flue gas to microalgal culture should be undertaken. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biomass combustion technologies for power generation

Energy Technology Data Exchange (ETDEWEB)

Wiltsee, G.A. Jr. [Appel Consultants, Inc., Stevenson Ranch, CA (United States); McGowin, C.R.; Hughes, E.E. [Electric Power Research Institute, Palo Alto, CA (United States)

1993-12-31

Technology in power production from biomass has been advancing rapidly. Industry has responded to government incentives such as the PURPA legislation in the US and has recognized that there are environmental advantages to using waste biomass as fuel. During the 1980s many new biomass power plants were built. The relatively mature stoker boiler technology was improved by the introduction of water-cooled grates, staged combustion air, larger boiler sizes up to 60 MW, higher steam conditions, and advanced sootblowing systems. Circulating fluidized-bed (CFB) technology achieved full commercial status, and now is the leading process for most utility-scale power applications, with more complete combustion, lower emissions, and better fuel flexibility than stoker technology. Bubbling fluidized-bed (BFB) technology has an important market niche as the best process for difficult fuels such as agricultural wastes, typically in smaller plants. Other biomass power generation technologies are being developed for possible commercial introduction in the 1990s. Key components of Whole Tree Energy{trademark} technology have been tested, conceptual design studies have been completed with favorable results, and plans are being made for the first integrated process demonstration. Fluidized-bed gasification processes have advanced from pilot to demonstration status, and the world`s first integrated wood gasification/combined cycle utility power plant is starting operation in Sweden in early 1993. Several European vendors offer biomass gasification processes commercially. US electric utilities are evaluating the cofiring of biomass with fossil fuels in both existing and new plants. Retrofitting existing coal-fired plants gives better overall cost and performance results than any biomass technologies;but retrofit cofiring is {open_quotes}fuel-switching{close_quotes} that provides no new capacity and is attractive only with economic incentives.

Development of generalised model for grate combustion of biomass

DEFF Research Database (Denmark)

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

for two reasons: 1) to improve emission understanding and reduction measures and 2) to improve boundary conditions for CFD-based furnace modelling. The selected approach has been based on a diffusion coefficient formulation, where conservation equations for the concentration of fuel are solved...... in a spatially resolved grid, much in the same manner as in a finite volume CFD code. Within this porous layer of fuel, gas flows according to the Ergun equation. The diffusion coefficient links the properties of the fuel to the grate type and vibration mode, and is determined for each combination of fuel, grate...... is big enough to represent real, full scale conditions, and yet small enough to be operational in terms of parameter studies of different nature. Apart from full SRO data, measurements (gas sampling, velocity, temperature, particle sampling) can be taken through a heated, water-cooled probe...

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-10-01

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

Suspension-Firing of Biomass

DEFF Research Database (Denmark)

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

2012-01-01

This paper is the second of two papers, describing probe measurements of deposit buildup and removal (shedding), conducted in a 350 MWth suspension-fired boiler, firing straw and wood. Investigations of deposit buildup and shedding have been made by use of an advanced online deposit probe and a s...

Co-firing coal and biomass blends and their influence on the post-combustion CO2 capture installation

Directory of Open Access Journals (Sweden)

Więckol-Ryk Angelika

2017-01-01

Research proved that co-firing of biomass in fossil fuel power plants is beneficial for PCC process. It may also reduce the corrosion of CO2 capture installation. The oxygen concentration in the flue gases from hard coal combustion was comparable with the respective value for a fuel blend of biomass content of 20% w/w. It was also noted that an increase in biomass content in a sample from 20 to 40 % w/w increased the concentration of oxygen in the flue gas streams. However, this concentration should not have a significant impact on the rate of amine oxidative degradation.

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-01-01

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

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

International Nuclear Information System (INIS)

Gauthier, S.

2004-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-08-01

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

Biomass energy in the making

International Nuclear Information System (INIS)

Anon.

2008-01-01

large volumes of organic waste, including waste from the paper and agro-food industries, household refuse, and biogas from the fermentation of treatment plant sludge. At the top of the list: the United States, which generated 56 TWh of bio-power in 2005, and Brazil, which favors bagasse from sugar cane and biogas from distillery effluents. The electrical efficiency of a small biomass plant is 30% at best (35% with the best available technologies), whereas coal-fired plants achieve about 45% efficiency and combined-cycle gas-fired plants hit the 55% mark. A problem is the varying composition of straw, wood or waste fueling the boiler, calling for robust, adaptable burners, grates and fluidized beds. Either that, or the fuel has to be converted to produce standardized fuel such as wood pellets or dried sludge, which only ups the price of the fuel even more. Converting forest waste into wood chips, for example, costs 40 to 50 euros per MWh of heat, whereas unprocessed sawmill residue costs 10 to 20 euros for the same MWh. Another obstacle to developing biomass for power generation is the problem of collecting the raw materials from far and wide. In addition to solid biomass, biogas can be used to recycle liquid or wet waste that is difficult to transport. Biogas is produced by the digestion of wet biomass in an oxygen-deprived environment. Biogas contains 40% to 70% methane. The methane can then be used to fuel a gas-fired plant. This is one of the best configurations there is, since the biomass comes directly from the final waste. It's a good illustration of the 'waste to wealth' concept, which consists of recycling waste to produce energy

Alkali resistant Cu/zeolite deNOx catalysts for flue gas cleaning in biomass fired applications

DEFF Research Database (Denmark)

Putluru, Siva Sankar Reddy; Riisager, Anders; Fehrmann, Rasmus

2011-01-01

to investigate the redox and acidic properties of the catalysts. The poisoning resistivity seems to be due to a combination of high surface area and strong acidity of the Cu/zeolite catalysts. The catalysts might be attractive alternatives to conventional catalysts for deNOx of flue gases from biomass fired...... power plants and other stationary industrial installations....

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

Energy Technology Data Exchange (ETDEWEB)

Wilen, C.; Rautalin, A.

1995-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

Wilen, C; Rautalin, A

1996-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-01

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

Fire in the Brazilian Amazon : 3. Dynamics of biomass, C, and nutrient pools in regenerating forests.

Science.gov (United States)

Hughes, R F; Kauffman, J B; Cummings, D L

2000-09-01

Regenerating forests have become a common land-cover type throughout the Brazilian Amazon. However, the potential for these systems to accumulate and store C and nutrients, and the fluxes resulting from them when they are cut, burned, and converted back to croplands and pastures have not been well quantified. In this study, we quantified pre- and post-fire pools of biomass, C, and nutrients, as well as the emissions of those elements, at a series of second- and third-growth forests located in the states of Pará and Rondônia, Brazil. Total aboveground biomass (TAGB) of second- and third-growth forests averaged 134 and 91 Mg ha -1 , respectively. Rates of aboveground biomass accumulation were rapid in these systems, but were not significantly different between second- and third-growth forests, ranging from 9 to 16 Mg ha -1 year -1 . Residual pools of biomass originating from primary forest vegetation accounted for large portions of TAGB in both forest types and were primarily responsible for TAGB differences between the two forest types. In second-growth forests this pool (82 Mg ha -1 ) represented 58% of TAGB, and in third-growth forests (40 Mg ha -1 ) it represented 40% of TAGB. Amounts of TAGB consumed by burning of second- and third-growth forests averaged 70 and 53 Mg ha -1 , respectively. Aboveground pre-fire pools in second- and third-growth forests averaged 67 and 45 Mg C ha -1 , 821 and 707 kg N ha -1 , 441 and 341 kg P ha -1 , and 46 and 27 kg Ca ha -1 , respectively. While pre-fire pools of C, N, S and K were not significantly different between second- and third-growth forests, pools of both P and Ca were significantly higher in second-growth forests. This suggests that increasing land use has a negative impact on these elemental pools. Site losses of elements resulting from slashing and burning these sites were highly variable: losses of C ranged from 20 to 47 Mg ha -1 ; N losses ranged from 306 to 709 kg ha -1 ; Ca losses ranged from 10 to 145 kg ha -1

Evaluation of ash deposits during experimental investigation of co-firing of Bosnian coal with wooden biomass

Energy Technology Data Exchange (ETDEWEB)

Smajevic, Izet; Kazagic, Anes [JP Elektroprivreda BiH d.d., Sarajevo (Bosnia and Herzegovina); Sarajevo Univ. (Bosnia and Herzegovina). Faculty of Mechanical Engineering

2008-07-01

The paper is addressed to the development and use different criteria for evaluation of ash deposits collected during experimental co-firing of Bosnian coals with wooden biomass. Spruce saw dust was used for the co-firing tests with the Kakanj brown coal and with a lignite blend consisted of the Dubrave lignite and the Sikulje lignite. The coal/biomass mixtures at 93:7 %w and at 80:20 %w were tested. Experimental lab-scale facility PF entrained flow reactor is used for the co-firing tests. The reactor allows examination of fouling/slagging behaviors and emissions at various and infinitely variable process temperature which can be set at will in the range from ambient to 1560 C. Ash deposits are collected on two non-cooled ceramic probes and one water-cooled metal surface. Six different criteria are developed and used to evaluate behavior of the ash deposits on the probes: ash deposit shape, state and structure, which are analyzed visually - photographically and optically by a microscope, rate of adhesion and ash deposit strength, analyzed by physic acting to the ash deposits, and finally deposition rate, determined as a mass of the deposit divided by the collecting area and the time of collecting. Furthermore, chemical composition analysis and AFT of the ash deposits were also done to provide additional information on the deposits. (orig.)

Modelling methods for co-fired pulverised fuel furnaces

Energy Technology Data Exchange (ETDEWEB)

L. Ma; M. Gharebaghi; R. Porter; M. Pourkashanian; J.M. Jones; A. Williams [University of Leeds, Leeds (United Kingdom). Energy and Resources Research Institute

2009-12-15

Co-firing of biomass and coal can be beneficial in reducing the carbon footprint of energy production. Accurate modelling of co-fired furnaces is essential to discover potential problems that may occur during biomass firing and to mitigate potential negative effects of biomass fuels, including lower efficiency due to lower burnout and NOx formation issues. Existing coal combustion models should be modified to increase reliability of predictions for biomass, including factors such as increased drag due to non-spherical particle sizes and accounting for organic compounds and the effects they have on NOx emission. Detailed biomass co-firing models have been developed and tested for a range of biomass fuels and show promising results. 32 refs., 4 figs., 3 tabs.

Birefringence Bragg Binary (3B) grating, quasi-Bragg grating and immersion gratings

Science.gov (United States)

Ebizuka, Noboru; Morita, Shin-ya; Yamagata, Yutaka; Sasaki, Minoru; Bianco, Andorea; Tanabe, Ayano; Hashimoto, Nobuyuki; Hirahara, Yasuhiro; Aoki, Wako

2014-07-01

A volume phase holographic (VPH) grating achieves high angular dispersion and very high diffraction efficiency for the first diffraction order and for S or P polarization. However the VPH grating could not achieve high diffraction efficiency for non-polarized light at a large diffraction angle because properties of diffraction efficiencies for S and P polarizations are different. Furthermore diffraction efficiency of the VPH grating extinguishes toward a higher diffraction order. A birefringence binary Bragg (3B) grating is a thick transmission grating with optically anisotropic material such as lithium niobate or liquid crystal. The 3B grating achieves diffraction efficiency up to 100% for non-polarized light by tuning of refractive indices for S and P polarizations, even in higher diffraction orders. We fabricated 3B grating with liquid crystal and evaluated the performance of the liquid crystal grating. A quasi-Bragg (QB) grating, which consists long rectangle mirrors aligned in parallel precisely such as a window shade, also achieves high diffraction efficiency toward higher orders. We fabricated QB grating by laminating of silica glass substrates and glued by pressure fusion of gold films. A quasi-Bragg immersion (QBI) grating has smooth mirror hypotenuse and reflector array inside the hypotenuse, instead of step-like grooves of a conventional immersion grating. An incident beam of the QBI grating reflects obliquely at a reflector, then reflects vertically at the mirror surface and reflects again at the same reflector. We are going to fabricate QBI gratings by laminating of mirror plates as similar to fabrication of the QB grating. We will also fabricate silicon and germanium immersion gratings with conventional step-like grooves by means of the latest diamond machining methods. We introduce characteristics and performance of these gratings.

Biomass burning in Africa: As assessment of annually burned biomass

International Nuclear Information System (INIS)

Delmas, R.A.; Loudjani, P.; Podaire, A.; Menaut, J.C.

1991-01-01

It is now established that biomass burning is the dominant phenomenon that controls the atmospheric chemistry in the tropics. Africa is certainly the continent where biomass burning under various aspects and processes is the greatest. Three different types of burnings have to be considered-bush fires in savanna zones which mainly affect herbaceous flora, forest fires due to forestation for shifting agriculture or colonization of new lands, and the use of wood as fuel. The net release of carbon resulting from deforestation is assumed to be responsible for about 20% of the CO 2 increase in the atmosphere because the burning of forests corresponds to a destorage of carbon from the biospheric reservoir. The amount of reactive of greenhouse gases emitted by biomass burning is directly proportional, through individual emission factors, to the biomass actually burned. This chapter evaluates the biomass annually burned on the African continent as a result of the three main burning processes previously mentioned

Prescribed fire experiences on crop residue removal for biomass exploitations. Application to the maritime pine forests in the Mediterranean Basin.

Science.gov (United States)

Molina, Juan Ramón; García, Juan Pedro; Fernández, Juan José; Rodríguez Y Silva, Francisco

2018-01-15

Socioeconomic changes, climate change, rural migration and fire exclusion have led to a high woody biomass accumulation increasing potential wildfire severity. Mechanical thinning and prescribed burning practices are commonly used to prevent large fires. The purpose of this study was to assess burning treatment effectiveness following mechanical thinning from biomass harvesting. Prescribed burning to reduce residue removal could help mitigate fire behavior, mainly in strategic management or critical focal points. Field samplings were conducted before and immediately after burnings on different environmental scenarios where fuel load was classified by categories. Prescribed fires reduced available fuel in all fuel categories, mainly in surface litter layer. Total fuel load reduction ranged from 59.07% to 86.18%. In this sense, fuel reduction effects were more pronounced when burns were conducted fewer than 10% on surface litter moisture. The difference in fuel consumption among scenarios was higher for most all woody fuel components and decomposition litter layer than for surface litter layer. Managers can use this information to design technical prescription to achieve the targets while decomposed litter retention maintaining the soil properties and biodiversity. Understanding the most effective "burn window" should help better plan prescribed burning, both in term of fire behavior and fuel consumption, without altering ecosystem properties. Copyright © 2017 Elsevier B.V. All rights reserved.

EOSLT Consortium Biomass Co-firing. WP 4. Biomass co-firing in oxy-fuel combustion. Part 1. Lab- Scale Experiments

Energy Technology Data Exchange (ETDEWEB)

Fryda, L.E. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

2011-07-15

In the frame of WP4 of the EOS LT Co-firing program, the ash formation and deposition of selected coal/biomass blends under oxyfuel and air conditions were studied experimentally in the ECN lab scale coal combustor (LCS). The fuels used were Russian coal, South African coal and Greek Lignite, either combusted separately or in blends with cocoa and olive residue. The first trial period included tests with the Russian and South African coals and their blends with cocoa, the second trial period included Lignite with olive residue tests and a final period firing only Lignite and Russian coal, mainly to check and verify the observed results. During the testing, also enriched air combustion was applied, in order to establish conclusions whether a systematic trend on ash formation and deposition exists, ranging from conventional air, to enriched air (improving post combustion applications) until oxyfuel conditions. A horizontal deposition probe equipped with thermocouples and heat transfer sensors for on line data acquisition, and a cascade impactor (staged filter) to obtain size distributed ash samples including the submicron range at the reactor exit were used. The deposition ratio and the deposition propensity measured for the various experimental conditions were higher in all oxyfuel cases. No significant variations in the ash formation mechanisms and the ash composition were established. Finally the data obtained from the tests performed under air and oxy-fuel conditions were utilised for chemical equilibrium calculations in order to facilitate the interpretation of the measured data; the results indicate that temperature dependence and fuels/blends ash composition are the major factors affecting gaseous compound and ash composition rather than the combustion environment, which seems to affect neither the ash and fine ash (submicron) formation, nor the ash composition. The ash deposition mechanisms were studied in more detail in Part II of this report.

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

DEFF Research Database (Denmark)

Montgomery, Melanie; Karlsson, A; Larsen, OH

2002-01-01

plants. The type of corrosion attack can be directly ascribed to the composition of the deposit and the metal surface temperature. A series of field tests have been undertaken in the various straw-fired power plants in Denmark, namely Masnedø, Rudkøbing and Ensted. Three types of exposure were undertaken......In Denmark, straw and other types of biomass are used for generating energy in power plants. Straw has the advantage that it is a "carbon dioxide neutral fuel" and therefore environmentally acceptable. Straw combustion is associated with corrosion problems which are not encountered in coal-fired...... to investigate corrosion: a) the exposure of metal rings on water/air cooled probes, b) the exposure of test tubes in a test superheater, and c) the exposure of test tubes in existing superheaters. Thus both austenitic steels and ferritic steels were exposed in the steam temperature range of 450-600°C...

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

DEFF Research Database (Denmark)

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

2015-01-01

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

Spatial and temporal distribution of tropical biomass burning

Science.gov (United States)

Hao, Wei Min; Liu, Mei-Huey

1994-12-01

A database for the spatial and temporal distribution of the amount of biomass burned in tropical America, Africa, and Asia during the late 1970s is presented with a resolution of 5° latitude × 5° longitude. The sources of burning in each grid cell have been quantified. Savanna fires, shifting cultivation, deforestation, fuel wood use, and burning of agricultural residues contribute about 50, 24, 10, 11, and 5%, respectively, of total biomass burned in the tropics. Savanna fires dominate in tropical Africa, and forest fires dominate in tropical Asia. A similar amount of biomass is burned from forest and savanna fires in tropical America. The distribution of biomass burned monthly during the dry season has been derived for each grid cell using the seasonal cycles of surface ozone concentrations. Land use changes during the last decade could have a profound impact on the amount of biomass burned and the amount of trace gases and aerosol particles emitted.

Biomass Cofiring in Coal-Fired Boilers

Energy Technology Data Exchange (ETDEWEB)

2004-06-01

Cofiring biomass-for example, forestry residues such as wood chips-with coal in existing boilers is one of the easiest biomass technologies to implement in a federal facility. The current practice is to substitute biomass for up to 20% of the coal in the boiler. Cofiring has many benefits: it helps to reduce fuel costs as well as the use of landfills, and it curbs emissions of sulfur oxide, nitrogen oxide, and the greenhouse gases associated with burning fossil fuels. This Federal Technology Alert was prepared by the Department of Energy's Federal Energy Management Program to give federal facility managers the information they need to decide whether they should pursue biomass cofiring at their facilities.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-03-01

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

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

International Nuclear Information System (INIS)

Gruber, Thomas; Scharler, Robert; Obernberger, Ingwald

2015-01-01

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

Understorey fire propagation and tree mortality on adjacent areas to an Amazonian deforestation fire

Science.gov (United States)

J.A. Carvalho; C.A. Gurgel Veras; E.C. Alvarado; D.V. Sandberg; S.J. Leite; R. Gielow; E.R.C. Rabelo; J.C. Santos

2010-01-01

Fire characteristics in tropical ecosystems are poorly documented quantitatively in the literature. This paper describes an understorey fire propagating across the edges of a biomass burn of a cleared primary forest. The experiment was carried out in 2001 in the Amazon forest near Alta Floresta, state of Mato Grosso, Brazil, as part of biomass burning experiments...

The FireWork air quality forecast system with near-real-time biomass burning emissions: Recent developments and evaluation of performance for the 2015 North American wildfire season

OpenAIRE

Pavlovic, Radenko; Chen, Jack; Anderson, Kerry; Moran, Michael D.; Beaulieu, Paul-Andr?; Davignon, Didier; Cousineau, Sophie

2016-01-01

ABSTRACT Environment and Climate Change Canada?s FireWork air quality (AQ) forecast system for North America with near-real-time biomass burning emissions has been running experimentally during the Canadian wildfire season since 2013. The system runs twice per day with model initializations at 00 UTC and 12 UTC, and produces numerical AQ forecast guidance with 48-hr lead time. In this work we describe the FireWork system, which incorporates near-real-time biomass burning emissions based on th...

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

Science.gov (United States)

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

2016-02-01

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

Materials for Waste Incinerators and Biomass Plants

DEFF Research Database (Denmark)

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

1998-01-01

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

A review on advances of torrefaction technologies for biomass processing

Energy Technology Data Exchange (ETDEWEB)

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

2012-12-15

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

deNOx catalysts for biomass combustion

DEFF Research Database (Denmark)

Kristensen, Steffen Buus

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

High Temperature Corrosion on Biodust Firing

DEFF Research Database (Denmark)

Okoro, Sunday Chukwudi

The high content of alkali metals and chlorine in biomass gives rise to fouling/slagging and corrosion of heat exchange components, such as superheaters, in biomass fired power plants. Increasing the lifetime of these components, and in addition, preventing unwarranted plant shutdowns due...... to their failure, requires understanding of the complex corrosion mechanisms, as well as development of materials that are resistant to corrosion under biomass firing conditions, thereby motivating the current work. To understand the mechanisms of corrosion attack, comprehensive analysis of corrosion products...... by the combined use of complementary information from microscopy, energy dispersive X-ray spectroscopy and various X-ray diffraction characterization techniques. In light of the wide variation in operating conditions in biomass fired power plants, systematic and well-controlled, but realistic laboratory scale...

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

OpenAIRE

W. Michael Griffin; Jeremy Michalek; H. Scott Matthews; Mohd Nor Azman Hassan

2014-01-01

Fossil fuels comprise 93% of Malaysia’s electricity generation and account for 36% of the country’s 2010 Greenhouse Gas (GHG) emissions. The government has targeted the installation of 330 MW of biomass electricity generation capacity by 2015 to avoid 1.3 Mt of CO 2 emissions annually and offset some emissions due to increased coal use. One biomass option is to co-fire with coal, which can result in reduced GHG emissions, coal use, and costs of electricity. A linear optimization cost model wa...

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

Directory of Open Access Journals (Sweden)

R. J. Weber

2010-07-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

2014-12-01

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

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

Science.gov (United States)

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.

High Temperature Corrosion in Biomass-Fired Boilers

DEFF Research Database (Denmark)

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

2002-01-01

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

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

CSIR Research Space (South Africa)

Wooster, MJ

2011-01-01

Full Text Available Biomass burning emissions factors are vital to quantifying trace gases releases from vegetation fires. Here the authors evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP), South Africa using ground-based open...

Numerical investigation of ash deposition in straw-fired boilers

DEFF Research Database (Denmark)

Kær, Søren Knudsen

in the design phase of straw-fired boilers. Some of the primary model outputs include improved heat transfer rate predictions and detailed information about local deposit formation rates. This information is essential when boiler availability and efficiency is to be estimated. A stand-alone program has been...... accumulation rates encountered during straw combustion in grate-fired boilers. The sub-models have been based on information about the combustion and deposition properties of straw gathered from the literature and combined into a single Computational Fluid Dynamics (CFD) based analysis tool which can aid...... transfer mechanisms have a pronounced influence on the combustion pattern. The combined set of sub-models has been evaluated using the straw-fired boiler at Masnedø CHP plant as a test case. The predicted grate combustion and KCl release patterns are in qualitative agreement with experimental findings...

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

DEFF Research Database (Denmark)

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

2015-01-01

The variable flue gas composition in biomass-fired plants, among other parameters, contributes to the complexityof high-temperature corrosion of materials. Systematic parameter studies are thus necessary to understand the underlyingcorrosion mechanisms. This paper investigates the effect of water...... (H2O) vapor content in the flue gas on the high-temperaturecorrosion of austenitic stainless steel (TP 347H FG) under laboratory conditions, to improve the understanding of corrosionmechanisms. Deposit-coated and deposit-free samples were isothermally exposed for 72 h in a synthetic flue gas...... previouslyreported findings suggest that an increase in the water vapor content will cause competitive adsorption on active sites....

Biomass torrefaction: A promising pretreatment technology for biomass utilization

Science.gov (United States)

Chen, ZhiWen; Wang, Mingfeng; Ren, Yongzhi; Jiang, Enchen; Jiang, Yang; Li, Weizhen

2018-02-01

Torrefaction is an emerging technology also called mild pyrolysis, which has been explored for the pretreatment of biomass to make the biomass more favorable for further utilization. Dry torrefaction (DT) is a pretreatment of biomass in the absence of oxygen under atmospheric pressure and in a temperature range of 200-300 degrees C, while wet torrrefaction (WT) is a method in hydrothermal or hot and high pressure water at the tempertures within 180-260 degrees C. Torrrefied biomass is hydrophobic, with lower moisture contents, increased energy density and higher heating value, which are more comparable to the characteristics of coal. With the improvement in the properties, torrefied biomass mainly has three potential applications: combustion or co-firing, pelletization and gasification. Generally, the torrefaction technology can accelerate the development of biomass utilization technology and finally realize the maximum applications of biomass energy.

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

NARCIS (Netherlands)

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

Biomass fuelled indirect fired micro turbine

Energy Technology Data Exchange (ETDEWEB)

Pritchard, D.

2005-07-01

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

Historic global biomass burning emissions for CMIP6 (BB4CMIP based on merging satellite observations with proxies and fire models (1750–2015

Directory of Open Access Journals (Sweden)

M. J. E. van Marle

2017-09-01

Full Text Available Fires have influenced atmospheric composition and climate since the rise of vascular plants, and satellite data have shown the overall global extent of fires. Our knowledge of historic fire emissions has progressively improved over the past decades due mostly to the development of new proxies and the improvement of fire models. Currently, there is a suite of proxies including sedimentary charcoal records, measurements of fire-emitted trace gases and black carbon stored in ice and firn, and visibility observations. These proxies provide opportunities to extrapolate emission estimates back in time based on satellite data starting in 1997, but each proxy has strengths and weaknesses regarding, for example, the spatial and temporal extents over which they are representative. We developed a new historic biomass burning emissions dataset starting in 1750 that merges the satellite record with several existing proxies and uses the average of six models from the Fire Model Intercomparison Project (FireMIP protocol to estimate emissions when the available proxies had limited coverage. According to our approach, global biomass burning emissions were relatively constant, with 10-year averages varying between 1.8 and 2.3 Pg C yr−1. Carbon emissions increased only slightly over the full time period and peaked during the 1990s after which they decreased gradually. There is substantial uncertainty in these estimates, and patterns varied depending on choices regarding data representation, especially on regional scales. The observed pattern in fire carbon emissions is for a large part driven by African fires, which accounted for 58 % of global fire carbon emissions. African fire emissions declined since about 1950 due to conversion of savanna to cropland, and this decrease is partially compensated for by increasing emissions in deforestation zones of South America and Asia. These global fire emission estimates are mostly suited for global analyses and

Emission performance and combustion efficiency of a conical fluidized-bed combustor firing various biomass fuels

International Nuclear Information System (INIS)

Permchart, W.; Kouprianov, V.I.

2004-01-01

This paper summarizes the results of an experimental study on combustion of three distinct biomass fuels (sawdust, rice husk and pre-dried sugar cane bagasse) in a single fluidized-bed combustor (FBC) with a conical bed using silica sand as the inert bed material. Temperature, CO, NO and O 2 concentrations along the combustor height as well as in flue (stack) gas were measured in the experimental tests. The effects of fuel properties and operating conditions (load and excess air) on these variables were investigated. Both CO and NO axial profiles were found to have a maximum whose location divides conventionally the combustor volume into formation (lower) and reduction (upper) regions for these pollutants. Based on CO emission and unburned carbon content in fly ash, the combustion efficiency of the conical FBC was quantified for the selected biomass fuels fired under different operating conditions. (Author)

Impacts of air pollutants from fire and non-fire emissions on the regional air quality in Southeast Asia

Science.gov (United States)

Lee, Hsiang-He; Iraqui, Oussama; Gu, Yefu; Hung-Lam Yim, Steve; Chulakadabba, Apisada; Yiu-Ming Tonks, Adam; Yang, Zhengyu; Wang, Chien

2018-05-01

Severe haze events in Southeast Asia caused by particulate pollution have become more intense and frequent in recent years. Widespread biomass burning occurrences and particulate pollutants from human activities other than biomass burning play important roles in degrading air quality in Southeast Asia. In this study, numerical simulations have been conducted using the Weather Research and Forecasting (WRF) model coupled with a chemistry component (WRF-Chem) to quantitatively examine the contributions of aerosols emitted from fire (i.e., biomass burning) versus non-fire (including fossil fuel combustion, and road dust, etc.) sources to the degradation of air quality and visibility over Southeast Asia. These simulations cover a time period from 2002 to 2008 and are driven by emissions from (a) fossil fuel burning only, (b) biomass burning only, and (c) both fossil fuel and biomass burning. The model results reveal that 39 % of observed low-visibility days (LVDs) can be explained by either fossil fuel burning or biomass burning emissions alone, a further 20 % by fossil fuel burning alone, a further 8 % by biomass burning alone, and a further 5 % by a combination of fossil fuel burning and biomass burning. Analysis of an 24 h PM2.5 air quality index (AQI) indicates that the case with coexisting fire and non-fire PM2.5 can substantially increase the chance of AQI being in the moderate or unhealthy pollution level from 23 to 34 %. The premature mortality in major Southeast Asian cities due to degradation of air quality by particulate pollutants is estimated to increase from ˜ 4110 per year in 2002 to ˜ 6540 per year in 2008. In addition, we demonstrate the importance of certain missing non-fire anthropogenic aerosol sources including anthropogenic fugitive and industrial dusts in causing urban air quality degradation. An experiment of using machine learning algorithms to forecast the occurrence of haze events in Singapore is also explored in this study. All of these

Impacts of air pollutants from fire and non-fire emissions on the regional air quality in Southeast Asia

Directory of Open Access Journals (Sweden)

H.-H. Lee

2018-05-01

Full Text Available Severe haze events in Southeast Asia caused by particulate pollution have become more intense and frequent in recent years. Widespread biomass burning occurrences and particulate pollutants from human activities other than biomass burning play important roles in degrading air quality in Southeast Asia. In this study, numerical simulations have been conducted using the Weather Research and Forecasting (WRF model coupled with a chemistry component (WRF-Chem to quantitatively examine the contributions of aerosols emitted from fire (i.e., biomass burning versus non-fire (including fossil fuel combustion, and road dust, etc. sources to the degradation of air quality and visibility over Southeast Asia. These simulations cover a time period from 2002 to 2008 and are driven by emissions from (a fossil fuel burning only, (b biomass burning only, and (c both fossil fuel and biomass burning. The model results reveal that 39 % of observed low-visibility days (LVDs can be explained by either fossil fuel burning or biomass burning emissions alone, a further 20 % by fossil fuel burning alone, a further 8 % by biomass burning alone, and a further 5 % by a combination of fossil fuel burning and biomass burning. Analysis of an 24 h PM2.5 air quality index (AQI indicates that the case with coexisting fire and non-fire PM2.5 can substantially increase the chance of AQI being in the moderate or unhealthy pollution level from 23 to 34 %. The premature mortality in major Southeast Asian cities due to degradation of air quality by particulate pollutants is estimated to increase from  ∼  4110 per year in 2002 to  ∼  6540 per year in 2008. In addition, we demonstrate the importance of certain missing non-fire anthropogenic aerosol sources including anthropogenic fugitive and industrial dusts in causing urban air quality degradation. An experiment of using machine learning algorithms to forecast the occurrence of haze events in Singapore is

Effects on NOx and SO2 Emissions during Co-Firing of Coal With Woody Biomass in Air Staging and Reburning

Directory of Open Access Journals (Sweden)

Nihad Hodžić

2018-02-01

Full Text Available Co-firing coal with different types of biomass is increasingly being applied in thermal power plants in Europe. The main motive for the use of biomass as the second fuel in coal-fired power plants is the reduction of CO2 emissions, and related financial benefits in accordance with the relevant international regulations and agreements. Likewise, the application of primary measures in the combustion chamber, which also includes air staging and/or reburning, results in a significant reduction in emission of polluting components of flue gases, in particular NOx emissions. In addition to being efficient and their application to new and future thermoblocks is practically unavoidable, their application and existing conventional combustion chamber does not require significant constructional interventions and is therefore relatively inexpensive. In this work results of experimental research of co-firing coals from Middle Bosnian basin with waste woody biomass are presented. Previously formed fuel test matrix is subjected to pulverized combustion under various temperatures and various technical and technological conditions. First of all it refers to the different mass ratio of fuel components in the mixture, the overall coefficient of excess air and to the application of air staging and/or reburning. Analysis of the emissions of components of the flue gases are presented and discussed. The impact of fuel composition and process temperature on the values of the emissions of components of the flue gas is determined. Additionally, it is shown that other primary measures in the combustion chamber are resulting in more or less positive effects in terms of reducing emissions of certain components of the flue gases into the environment. Thus, for example, the emission of NOx of 989 mg/ measured in conventional combustion, with the simultaneous application of air staging and reburning is reduced to 782 mg/, or by about 21%. The effects of the primary measures

Impact of Wildfire on Microbial Biomass in Critical Zone Observatory

Science.gov (United States)

Murphy, M. A.; Fairbanks, D.; Chorover, J.; Gallery, R. E.; Rich, V. I.

2014-12-01

The recovery of the critical zone following disturbances such as wildfire is not fully understood. Wildfires have increased in size and intensity in western US forests in recent years and these fires influence soil microbial communities, both in composition and overall biomass. Studies have typically shown a 50% post-fire decline in overall microbial biomass (µg per g soil) that can persist for years. There is however, some variability in the severity of biomass decline, and its relationship with burn severity and landscape position have not yet been studied. Since microbial biomass has a cascade of impacts in soil systems, from helping control the rate and diversity the biogeochemical processes occurring, to promoting soil fertility, to impacting the nature and structure of soil carbon (C), fire's lasting impact on it is one mechanistic determinant of the overall post-fire recovery of impacted ecosystems. Additionally, microbial biomass measurements hold potential for testing and incorporation into land surface models (NoahMP, CLM, etc.) in order to improve estimates of long-term effects of climate change and disturbances such as fire on the C cycle. In order to refine our understanding of the impact of fire on microbial biomass and then relate that to biogeochemical processes and ecosystem recovery, we used chloroform fumigation extraction to quantify total microbial biomass C (Cmic ). One year after the June 2013 Thompson Ridge fire in the Jemez River Basin Critical Zone Observatory, we are measuring the Cmic of 22 sites across a gradient of burn severities and 4 control unburned sites, from six depth intervals at each site (0-2, 2-5, 5-10, 10-20, 20-30, and 30-40 cm). We hypothesize that the decrease in microbial biomass in burned sites relative to control sites will correlate with changes in soil biogeochemistry related to burn severity; and that the extent of the impact on biomass will be inversely related to depth in the soil column. Additionally, as the

Optical fiber Bragg gratings. Part II. Modeling of finite-length gratings and grating arrays.

Science.gov (United States)

Passaro, Vittorio M N; Diana, Roberto; Armenise, Mario N

2002-09-01

A model of both uniform finite-length optical fiber Bragg gratings and grating arrays is presented. The model is based on the Floquet-Bloch formalism and allows rigorous investigation of all the physical aspects in either single- or multiple-periodic structures realized on the core of a monomodal fiber. Analytical expressions of reflectivity and transmittivity for both single gratings and grating arrays are derived. The influence of the grating length and the index modulation amplitude on the reflected and transmitted optical power for both sinusoidal and rectangular profiles is evaluated. Good agreement between our method and the well-known coupled-mode theory (CMT) approach has been observed for both single gratings and grating arrays only in the case of weak index perturbation. Significant discrepancies exist there in cases of strong index contrast because of the increasing approximation of the CMT approach. The effects of intragrating phase shift are also shown and discussed.

Influence of Preoxidation on High-Temperature Corrosion of a FeCrAl Alloy Under Conditions Relevant to Biomass Firing

DEFF Research Database (Denmark)

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

2018-01-01

Preoxidation of a commercial FeCrAl alloy (Kanthal APM) was evaluated as a surface modification approach to reduce alkali chloride-induced corrosion during biomass firing in power plants. Samples of the alloy preoxidized at 900 °C in O2 or O2 + 10 vol% H2O, and at 1100 °C in O2, were coated...

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

Science.gov (United States)

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

2014-01-01

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 5 a wide variety of conditions is a critical part of forecasting the impact of these fires...

Suspension-Firing of Biomass

DEFF Research Database (Denmark)

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

2012-01-01

This paper is Part 1 in a series of two describing probe measurements of deposit build-up and removal (shedding) in a 350 MWth suspension boiler, firing straw and wood. The influence of fuel type (straw share in wood), probe exposure time, probe surface temperature (500, 550, and 600 °C), and flu...

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-05-01

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

Cofiring versus biomass-fired power plants: GHG (Greenhouse Gases) emissions savings comparison by means of LCA (Life Cycle Assessment) methodology

International Nuclear Information System (INIS)

Sebastian, F.; Royo, J.; Gomez, M.

2011-01-01

One way of producing nearly CO 2 free electricity is by using biomass as a combustible. In many cases, removal of CO 2 in biomass grown is almost the same as the emissions for the bioelectricity production at the power plant. For this reason, bioelectricity is generally considered CO 2 neutral. For large-scale biomass electricity generation two alternatives can be considered: biomass-only fired power plants, or cofiring in an existing coal power plant. Among other factors, two important aspects should be analyzed in order to choose between the two options. Firstly, which is the most appealing alternative if their Greenhouse Gases (GHG) Emissions savings are taken into account. Secondly, which biomass resource is the best, if the highest impact reduction is sought. In order to quantify all the GHG emissions related to each system, a Life Cycle Assessment (LCA) methodology has been performed and all the processes involved in each alternative have been assessed in a cradle-to-grave manner. Sensitivity analyses of the most dominant parameters affecting GHG emissions, and comparisons between the obtained results, have also been carried out.

Renew, reduce or become more efficient? The climate contribution of biomass co-combustion in a coal-fired power plant

International Nuclear Information System (INIS)

Miedema, Jan H.; Benders, René M.J.; Moll, Henri C.; Pierie, Frank

2017-01-01

Highlights: • Coal mining is more energy and CO_2 efficient than biomass production. • Co-combustion of 60% biomass with coal doubles mass transport compared to 100% coal. • Low co-combustion levels reduce GHG emissions, but the margins are small. • Total supply chain efficiency is the highest for the coal reference at 41.2%. - Abstract: Within this paper, biomass supply chains, with different shares of biomass co-combustion in coal fired power plants, are analysed on energy efficiency, energy consumption, renewable energy production, and greenhouse gas (GHG) emissions and compared with the performance of a 100% coal supply chain scenario, for a Dutch situation. The 60% biomass co-combustion supply chain scenarios show possibilities to reduce emissions up to 48%. The low co-combustion levels are effective to reduce GHG emissions, but the margins are small. Currently co-combustion of pellets is the norm. Co-combustion of combined torrefaction and pelleting (TOP) shows the best results, but is also the most speculative. The indicators from the renewable energy directive cannot be aligned. When biomass is regarded as scarce, co-combustion of small shares or no co-combustion is the best option from an energy perspective. When biomass is regarded as abundant, co-combustion of large shares is the best option from a GHG reduction perspective.

Life cycle assessment of biomass-to-energy systems in Ireland modelled with biomass supply chain optimisation based on greenhouse gas emission reduction

International Nuclear Information System (INIS)

Murphy, Fionnuala; Sosa, Amanda; McDonnell, Kevin; Devlin, Ger

2016-01-01

The energy sector is the major contributor to GHG (greenhouse gas emissions) in Ireland. Under EU Renewable energy targets, Ireland must achieve contributions of 40%, 12% and 10% from renewables to electricity, heat and transport respectively by 2020, in addition to a 20% reduction in GHG emissions. Life cycle assessment methodology was used to carry out a comprehensive, holistic evaluation of biomass-to-energy systems in 2020 based on indigenous biomass supply chains optimised to reduce production and transportation GHG emissions. Impact categories assessed include; global warming, acidification, eutrophication potentials, and energy demand. Two biomass energy conversion technologies are considered; co-firing with peat, and biomass CHP (combined heat and power) systems. Biomass is allocated to each plant according to a supply optimisation model which ensures minimal GHG emissions. The study shows that while CHP systems produce lower environmental impacts than co-firing systems in isolation, determining overall environmental impacts requires analysis of the reference energy systems which are displaced. In addition, if the aims of these systems are to increase renewable energy penetration in line with the renewable electricity and renewable heat targets, the optimal scenario may not be the one which achieves the greatest environmental impact reductions. - Highlights: • Life cycle assessment of biomass co-firing and CHP systems in Ireland is carried out. • GWP, acidification and eutrophication potentials, and energy demand are assessed. • Biomass supply is optimised based on minimising GHG emissions. • CHP systems cause lower environmental impacts than biomass co-firing with peat. • Displacing peat achieves higher GHG emission reductions than replacing fossil heat.

The impact of fire on sand dune stability: Surface coverage and biomass recovery after fires on Western Australian coastal dune systems from 1988 to 2016

Science.gov (United States)

Shumack, Samuel; Hesse, Paul; Turner, Liam

2017-12-01

This study aims to determine the common response of coastal sand dunes in Western Australia (WA) to fire on decadal time-scales, in terms of ecological-geomorphic-climatic interactions to test the hypothesis that fire plays a role in coastal dune destabilisation. Fires are commonly suggested to have contributed to widespread dune reactivation in Australia and globally, a hypothesis that is relatively untested. We used data from the Landsat Thematic Mapper, Enhanced Thematic Mapper Plus, and Operational Land Imager missions to monitor changes in surface coverage on coastal sand dunes in south-west WA after fires. We analysed 31 fire scars from 1988 to 2016 in two Landsat scenes on the west and south coast of WA. Recovery ratios derived from the Normalised Difference Vegetation Index (NDVI) were used to monitor patterns in post-fire biomass and surface cover. Recovery ratios are correlated with indices of burn severity, and meteorological data to investigate relationships. We also used Maximum Likelihood Classification to monitor changes in bare sand area. Results suggest that recovery followed a strongly consistent pattern, and is characterised by rapid vegetation cover re-establishment within six to twelve months. Prior to this, some aeolian activity may have occurred but without substantial surface changes. Initial germination and/or resprouting were followed by steady growth up to seven years, where NDVI typically neared pre-fire values. Some variation in early recovery occurred between the west and south coast, possibly owing to relative proportions of reseeding and resprouting plants. A log regression explained 75% of the recovery pattern (79% on the south coast). Precipitation had some ability to explain recovery up to nine months post-fire (r2 = 0.29 to 0.54). No relationships were observed between estimates of burn severity and recovery. After nine months, the biggest cause of spatial variation in recovery was the pre-fire community composition and related

Use of biomass for clean and efficient production of heat and power. Phase 2

Energy Technology Data Exchange (ETDEWEB)

Glarborg, P.; Lans, R. van der; Frandsen, J.B.F.; Johnsson, J.E.; Jensen, A.; Kiil, S.; Dam-Johansen, K.

2001-03-01

The present EFP98 project is the second phase of a long-term, strategic research project, the aim of which is to facilitate the use of significant amounts of biomass in the production of power and heat. The project deals with combustion and emission issues related to the use of biomass, specifically combustion of straw on a grate and wet flue gas desulphurization. A mathematical model for combustion of straw on a grate is developed as a tool to improve the understanding of this process. The model includes heat transfer to and in the bed as well as pyrolysis and char oxidation. To verify the model and to obtain a better understanding of fixed-bed straw combustion, a number of bench-scale laboratory experiments have been conducted at TNO in Holland. Predicted combustion rates and bed temperatures were in fairly good agreement with experimental fixed-bed data. A parameter analysis has identified the sensitivity of modeling predictions towards important parameters in the model. Measuring programs on straw firing have been conducted at Enstedvaerket and Masnedoe. Measuring results include gas temperature and gas composition (O{sub 2}, CO{sub 2}, CO. SO{sub 2}, NO) from different positions in the boiler. Data from Masnedoe include also results from co-firing of straw with other biomass fuels (25-35%). The results indicate that co-firing in the quantities does not significantly affect emissions. Nitrogen oxides emissions from Masnedoevaerket were found to be significantly higher than those of Ensted. The work on wet flue gas desulphurization on aimed to provide the information necessary to optimize and further develop the process. The main focus was fuel and sorbent flexibility, use of the waste product from the semi-dry FGD process as a sorbent in wet FGD, and ways of optimizing the Wet FGD process with respect to a high degree of desulphurization, a low content of residual limestone in the gypsum and a continuous steady state operation of the FGD plant. Laboratory

Fire-induced Carbon Emissions and Regrowth Uptake in Western U.S. Forests: Documenting Variation Across Forest Types, Fire Severity, and Climate Regions

Science.gov (United States)

Ghimire, Bardan; Williams, Christopher A.; Collatz, George James; Vanderhoof, Melanie

2012-01-01

The forest area in the western United States that burns annually is increasing with warmer temperatures, more frequent droughts, and higher fuel densities. Studies that examine fire effects for regional carbon balances have tended to either focus on individual fires as examples or adopt generalizations without considering how forest type, fire severity, and regional climate influence carbon legacies. This study provides a more detailed characterization of fire effects and quantifies the full carbon impacts in relation to direct emissions, slow release of fire-killed biomass, and net carbon uptake from forest regrowth. We find important variations in fire-induced mortality and combustion across carbon pools (leaf, live wood, dead wood, litter, and duff) and across low- to high-severity classes. This corresponds to fire-induced direct emissions from 1984 to 2008 averaging 4 TgC/yr and biomass killed averaging 10.5 TgC/yr, with average burn area of 2723 sq km/yr across the western United States. These direct emission and biomass killed rates were 1.4 and 3.7 times higher, respectively, for high-severity fires than those for low-severity fires. The results show that forest regrowth varies greatly by forest type and with severity and that these factors impose a sustained carbon uptake legacy. The western U.S. fires between 1984 and 2008 imposed a net source of 12.3 TgC/yr in 2008, accounting for both direct fire emissions (9.5 TgC/yr) and heterotrophic decomposition of fire-killed biomass (6.1 TgC yr1) as well as contemporary regrowth sinks (3.3 TgC/yr). A sizeable trend exists toward increasing emissions as a larger area burns annually.

Biomass co-firing in coal power plants in the Netherlands. Effects on performance and air pollutant emissions

Energy Technology Data Exchange (ETDEWEB)

Smekens, K. [ECN Policy Studies, Petten (Netherlands)

2013-07-15

This note is intended for use in the UNECE (United Nations Economic Commission for Europe)-EGTEI (Expert Group on Techno-Economic Issues) work related to cost of emission reduction technologies for large combustion plants (LCP). This work is coordinated by KIT (Karlsruhe) and CITEPA (Paris). As the Netherlands is considered to be a valuable country for data regarding biomass co-firing in large coal fired power plants, EGTEI expressed its interest on data ECN has available. For this purpose, based on available data from annual environmental reports of power plants, ECN has looked into the relationship between the percentage of co -firing and the plant performance. It should be noted that the evaluation has been based on annual data, not on real-time simultaneous measurements of the different parameters mentioned in this note. Cumulative annual data give no insights in e.g. the effects of the load factor, of start-ups or shut-downs, seasonal circumstances, fuel qualities, etc. Therefore, the findings in this report should be treated with due care and not be generalised.

Effects of fire on soil nitrogen dynamics and microbial biomass in savannas of Central Brazil

Directory of Open Access Journals (Sweden)

Nardoto Gabriela Bielefeld

2003-01-01

Full Text Available The objective of this work was to study the effects of fire on net N mineralization and soil microbial biomass in burned and unburned cerrado stricto sensu sites. The study was carried out from April 1998 to April 2000. The pH values were significantly higher in the burned site while soil moisture content was significantly higher in the unburned site (P<0.05. The soil C/N ratio was 22/1 and the available NO3-N ranged between 1.5 and 2.8 mg kg-¹ dry weight. However, the NH4-N concentration ranged between 3 and 34 mg kg-1 dry weight in the burned site and between 3 and 22 mg kg-1 dry weight in the unburned site. The NH4-N increased after fire, but no significant changes were observed for NO3-N (P<0.05. The NO3-N accumulation occurred in short periods during the rainy season. The rates of net N mineralization increased during the rainy season while reductions in soil microbial biomass were observed at both sites. This suggested that the peak in microbial activities occurred with the first rain events, with an initial net immobilization followed by net mineralization. Both sites presented the same pattern for mineralization/immobilization, however, the amount of inorganic-N cycled annually in unburned site was 14.7 kg ha-1 per year while the burned site presented only 3.8 kg ha-¹ of inorganic-N, one year after the burning.

Jointly optimizing selection of fuel treatments and siting of forest biomass-based energy production facilities for landscape-scale fire hazard reduction.

Science.gov (United States)

Peter J. Daugherty; Jeremy S. Fried

2007-01-01

Landscape-scale fuel treatments for forest fire hazard reduction potentially produce large quantities of material suitable for biomass energy production. The analytic framework FIA BioSum addresses this situation by developing detailed data on forest conditions and production under alternative fuel treatment prescriptions, and computes haul costs to alternative sites...

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

DEFF Research Database (Denmark)

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-11-01

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

Model based control of grate combustion; Modellbaserad roststyrning

Energy Technology Data Exchange (ETDEWEB)

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

2006-12-15

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

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

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

Directory of Open Access Journals (Sweden)

K. M. Sakamoto

2016-06-01

Full Text Available 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

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

Science.gov (United States)

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

2016-06-01

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

Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

Science.gov (United States)

Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

2016-03-01

The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia.

Relationships between annual plant productivity, nitrogen deposition and fire size in low-elevation California desert scrub

Science.gov (United States)

Rao, Leela E.; Matchett, John R.; Brooks, Matthew L.; Johns, Robert; Minnich, Richard A.; Allen, Edith B.

2014-01-01

Although precipitation is correlated with fire size in desert ecosystems and is typically used as an indirect surrogate for fine fuel load, a direct link between fine fuel biomass and fire size has not been established. In addition, nitrogen (N) deposition can affect fire risk through its fertilisation effect on fine fuel production. In this study, we examine the relationships between fire size and precipitation, N deposition and biomass with emphasis on identifying biomass and N deposition thresholds associated with fire spreading across the landscape. We used a 28-year fire record of 582 burns from low-elevation desert scrub to evaluate the relationship of precipitation, N deposition and biomass with the distribution of fire sizes using quantile regression. We found that models using annual biomass have similar predictive ability to those using precipitation and N deposition at the lower to intermediate portions of the fire size distribution. No distinct biomass threshold was found, although within the 99th percentile of the distribution fire size increased with greater than 125 g m–2 of winter fine fuel production. The study did not produce an N deposition threshold, but did validate the value of 125 g m–2 of fine fuel for spread of fires.

Effect of flue gas composition on deposit induced high temperature corrosion under laboratory conditions mimicking biomass firing. Part II: Exposures in SO2 containing atmospheres

DEFF Research Database (Denmark)

Okoro, Sunday Chukwudi; Kiamehr, Saeed; Montgomery, Melanie

2017-01-01

SO2. Scanning electron microscopy (SEM), energy dispersive X-rayspectroscopy (EDS) and X-ray diffraction (XRD) techniques werecomplimentarily applied to characterize the resulting corrosion products. Apartially molten K2SO4-layer formed on KCl coated specimens, and corrosionresulted in localized......In biomass fired power plants, the fast corrosion of superheaters is facilitatedby the presence of corrosive flue gas species, for example, SO2, which arereleased during combustion. To understand the role of the gas species on thecorrosion process, comparative laboratory exposures of deposit (KCl......)-coatedand deposit-free austenitic stainless steel (TP 347H FG) samples to gas mixturescontaining SO2 was carried out, under conditions relevant to biomass-firing.Exposures were conducted isothermally at 560 8C for 72 h, in oxidizingsulphidizing,and oxidizing-sulphidizing-chlorinating gas mixtures containing60 ppmv...

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

Science.gov (United States)

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

2015-01-01

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...

'Biomass lung': primitive biomass combustion and lung disease

International Nuclear Information System (INIS)

Baris, Y. I.; Seyfikli, Z.; Demir, A.; Hoskins, J. A.

2002-01-01

Domestic burning of biomass fuel is one of the most important risk factors for the development of respiratory diseases and infant mortality. The fuel which causes the highest level of disease is dung. In the rural areas of developing countries some 80% of households rely on biomass fuels for cooking and often heating as well and so suffer high indoor air pollution. Even when the fire or stove is outside the home those near it are still exposed to the smoke. In areas where the winters are long and cold the problem is aggravated since the fire or stove is indoors for many months of the year. The consequence of biomass burning is a level of morbidity in those exposed to the smoke as well as mortality. The rural areas of Turkey are among many in the world where biomass is the major fuel source. In this case report 8 patients from rural areas, particularly Anatolia, who used biomass are presented. Many of these are non-smoking, female patients who have respiratory complaints and a clinical picture of the chronic lung diseases which would have been expected if they had been heavy smokers. Typically patients cook on the traditional 'tandir' stove using dung and crop residues as the fuel. Ventilation systems are poor and they are exposed to a high level of smoke pollution leading to cough and dyspnoea. Anthracosis is a common outcome of this level of exposure and several of the patients developed lung tumours. The findings from clinical examination of 8 of these patients (2 M, 6 F) are presented together with their outcome where known. (author)

Fire behavior in Mediterranean shrub species (Maquis)

African Journals Online (AJOL)

STORAGESEVER

2008-11-19

Nov 19, 2008 ... 36°C. Of the fire behavior characteristics, rate of spread ranged from 0.38 to 7.35 m min-1, fuel ... Key words: Fire behavior, fuel biomass, Maquis, shrubland, Turkey. ...... Two rural/urban interface fires in the Wellington.

The FireWork air quality forecast system with near-real-time biomass burning emissions: Recent developments and evaluation of performance for the 2015 North American wildfire season.

Science.gov (United States)

Pavlovic, Radenko; Chen, Jack; Anderson, Kerry; Moran, Michael D; Beaulieu, Paul-André; Davignon, Didier; Cousineau, Sophie

2016-09-01

Environment and Climate Change Canada's FireWork air quality (AQ) forecast system for North America with near-real-time biomass burning emissions has been running experimentally during the Canadian wildfire season since 2013. The system runs twice per day with model initializations at 00 UTC and 12 UTC, and produces numerical AQ forecast guidance with 48-hr lead time. In this work we describe the FireWork system, which incorporates near-real-time biomass burning emissions based on the Canadian Wildland Fire Information System (CWFIS) as an input to the operational Regional Air Quality Deterministic Prediction System (RAQDPS). To demonstrate the capability of the system we analyzed two forecast periods in 2015 (June 2-July 15, and August 15-31) when fire activity was high, and observed fire-smoke-impacted areas in western Canada and the western United States. Modeled PM2.5 surface concentrations were compared with surface measurements and benchmarked with results from the operational RAQDPS, which did not consider near-real-time biomass burning emissions. Model performance statistics showed that FireWork outperformed RAQDPS with improvements in forecast hourly PM2.5 across the region; the results were especially significant for stations near the path of fire plume trajectories. Although the hourly PM2.5 concentrations predicted by FireWork still displayed bias for areas with active fires for these two periods (mean bias [MB] of -7.3 µg m(-3) and 3.1 µg m(-3)), it showed better forecast skill than the RAQDPS (MB of -11.7 µg m(-3) and -5.8 µg m(-3)) and demonstrated a greater ability to capture temporal variability of episodic PM2.5 events (correlation coefficient values of 0.50 and 0.69 for FireWork compared to 0.03 and 0.11 for RAQDPS). A categorical forecast comparison based on an hourly PM2.5 threshold of 30 µg m(-3) also showed improved scores for probability of detection (POD), critical success index (CSI), and false alarm rate (FAR). Smoke from wildfires

Thermodynamic simulation of a multi-step externally fired gas turbine powered by biomass

International Nuclear Information System (INIS)

Durante, A.; Pena-Vergara, G.; Curto-Risso, P.L.; Medina, A.; Calvo Hernández, A.

2017-01-01

Highlights: • A realistic model for an EFGT fueled with solid biomass is presented. • Detailed submodels for the HTHE and the chemical reactions are incorporated. • An arbitrary number of compression and expansion stages is considered. • Model validation leads to good agreement with experimental results. • A layout with two-stage compression leads to good efficiencies and power output. - Abstract: A thermodynamic model for a realistic Brayton cycle, working as an externally fired gas turbine fueled with biomass is presented. The use of an external combustion chamber, allows to burn dirty fuels to preheat pure air, which is the working fluid for the turbine. It also avoids direct contact of ashes with the turbine blades, resulting in a higher life cycle for the turbine. The model incorporates a high temperature heat exchanger and an arbitrary number of turbines and compressors, with the corresponding number of intercoolers and reheaters. It considers irreversibilities such as non-isentropic compressions and expansions, and pressure losses in heat input and release. The composition and temperature of the combustion gases, as well as the variable flow rate of air and combustion gases, are calculated for specific biomasses. The numerical model for a single stage configuration has been validated by comparing its predictions with the data sheets of two commercial turbines. Results are in good agreement. Curves on the dependence of thermal efficiency and power output with the overall pressure ratio will be shown for several plant configurations with variable number of compression/expansion stages. Also the influence of different types of biomasses and their moisture will be analyzed on parameters such as fuel consumption and exhaust gases temperature. For a single step plant layout fueled with eucalyptus wood an efficiency of 23% is predicted, whereas for a configuration with two compressors and one turbine efficiency increases up to 25%. But it is remarkable

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

Science.gov (United States)

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

2013-01-01

The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

R. J. Parker

2016-08-01

Full Text Available 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

Availability of Dutch biomass for electricity and heat in 2020

International Nuclear Information System (INIS)

Koppejan, J.; Elbersen, W.; Meeusen, M.; Bindraban, P.

2009-11-01

Availability of biomass is an important factor in realizing the Dutch targets for renewable energy. This study maps the availability of Dutch biomass in the framework of alternative applications and sustainability requirements, today and in the future. The conclusion is drawn that there is approximately 13 to 16 million tons of dry biomass available for energy generation in the Netherlands in 2020. This is 30 to 40% of the amount of biomass that is annually used in the Netherlands, generating 53 to 94 PJ of final energy, avoiding 101 to 157 PJ of fossil energy. This availability of biomass and the energy that is generated from the biomass can increase further after 2020. In addition, biomass will also be imported, especially for combustion and co-firing in coal-fired power plants and for the production of transport fuels. [nl

Effective technology of wood and gaseous fuel co-firing for clean energy production

International Nuclear Information System (INIS)

Zake, M.; Barmina, I.; Gedrovics, M.; Desnickis, A.

2007-01-01

The main aim of the study was to develop and optimise a small-scale experimental co-firing technique for the effective and clean heat energy production by replacing a proportion of fossil fuel (propane) with renewable one (wood biomass). Technical solutions of propane co-fire presenting two different ways of additional heat supply to the wood biomass are proposed and analysed. The experiments have shown that a better result can be obtained for the direct propane co-fire of the wood biomass, when the rate of wood gasification and the ignition of volatiles are controlled by additional heat energy supply to the upper portion of wood biomass. A less effective though cleaner way of heat energy production is the direct propane co-fire of volatiles when low-temperature self-sustaining burnout of the wood biomass controls the rate of the volatile formation, while additional heat energy supply to the flow of volatiles controls their burnout. The effect of propane co-fire on the heat production rate and the composition of polluting emissions is studied and analysed for different rates of the additional heat supply to the wood biomass and of the swirling air supply as well as for different charge of wood biomass above the inlet of the propane flame flow. (Authors)

Biomass as a fuel: Advantages, limitations and possibilities

International Nuclear Information System (INIS)

McBurney, B.

1997-01-01

This presentation briefly outlines major issues related to the use of biomass fuels. Advantages and disadvantages of biomass fuels are identified, as well as major factors that may facilitate greater use of biomass fuels. Highlights of the US DOE Biomass Power Program, program activities, and demonstration projects are presented. Some statistical and economic data are provided, including biomass fueled electric capacity, biomass energy consumption by sector, and fuel cost savings and greenhouse gas emissions reductions for four biomass co-fired units

Co-firing: panacea or potential monster?

Energy Technology Data Exchange (ETDEWEB)

Grundy, M.; Lilley, P. [Mott MacDonald Ltd., Brighton (United Kingdom). Energy Division

2004-01-01

Co-firing with fossil fuels could well be the only practical and economic way to introduce a significant biomass contribution to UK renewables. But, in the hands of the large generators, co-firing is a potential monster, capable of destroying the carefully-constructed incentive structure for 'real' renewables such as wind power and dedicated biomass plants. Both views contain an element of truth, but the conflict between them could endanger the infant energy crop industry. 1 fig., 2 photos.

Changes in vegetation structure and aboveground biomass in ...

African Journals Online (AJOL)

Changes in vegetation structure and aboveground biomass in response to traditional rangeland management practices in Borana, southern Ethiopia. ... managed by prescribed fire for five years and grazed only post-fire during dry seasons.

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-09-01

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

Overview of the Fire Lab at Missoula Experiments (FLAME)

Science.gov (United States)

S. M. Kreidenweis; J. L. Collett; H. Moosmuller; W. P. Arnott; WeiMin Hao; W. C. Malm

2010-01-01

The Fire Lab at Missoula Experiments (FLAME) used a series of open biomass burns, conducted in 2006 and 2007 at the Forest Service Fire Science Laboratory in Missoula, MT, to characterize the physical, chemical and optical properties of biomass combustion emissions. Fuels were selected primarily based on their projected importance for emissions from prescribed and wild...

Biomass Pyrolysis in DNS of Turbulent Particle-Laden Flow

NARCIS (Netherlands)

Russo, E; Fröhlich, Jochen; Kuerten, Johannes G.M.; Geurts, Bernardus J.; Armenio, Vincenzo

2015-01-01

Biomass is important for co-firing in coal power plants thereby reducing CO2 emissions. Modeling the combustion of biomass involves various physical and chemical processes, which take place successively and even simultaneously [1, 2]. An important step in biomass combustion is pyrolysis, in which

Smouldering Subsurface Fires in the Earth System

Science.gov (United States)

Rein, Guillermo

2010-05-01

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

Evaluation of sampling strategies to estimate crown biomass

Science.gov (United States)

Krishna P Poudel; Hailemariam Temesgen; Andrew N Gray

2015-01-01

Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the tree. Crown biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products, fuel load assessments and fire management strategies, and wildfire...

Biomass combustion gas turbine CHP

Energy Technology Data Exchange (ETDEWEB)

Pritchard, D.

2002-07-01

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

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

Directory of Open Access Journals (Sweden)

Judit Lecina-Diaz

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

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

Science.gov (United States)

Lecina-Diaz, Judit; Alvarez, Albert; Retana, Javier

2014-01-01

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

Persistent Effects of Fire Severity on Early Successional Forests in Interior Alaska

Science.gov (United States)

Shenoy, Aditi; Johnstone, Jill F.; Kasischke, Eric S.; Kielland, Knut

2011-01-01

There has been a recent increase in the frequency and extent of wildfires in interior Alaska, and this trend is predicted to continue under a warming climate. Although less well documented, corresponding increases in fire severity are expected. Previous research from boreal forests in Alaska and western Canada indicate that severe fire promotes the recruitment of deciduous tree species and decreases the relative abundance of black spruce (Picea mariana) immediately after fire. Here we extend these observations by (1) examining changes in patterns of aspen and spruce density and biomass that occurred during the first two decades of post-fire succession, and (2) comparing patterns of tree composition in relation to variations in post-fire organic layer depth in four burned black spruce forests in interior Alaska after 10-20 years of succession.Wefound that initial effects of fire severity on recruitment and establishment of aspen and black spruce were maintained by subsequent effects of organic layer depth and initial plant biomass on plant growth during post-fire succession. The proportional contribution of aspen (Populus tremuloides) to total stand biomass remained above 90% during the first and second decades of succession in severely burned sites, while in lightly burned sites the proportional contribution of aspen was reduced due to a 40- fold increase in spruce biomass in these sites. Relationships between organic layer depth and stem density and biomass were consistently negative for aspen, and positive or neutral for black spruce in all four burns. Our results suggest that initial effects of post-fire organic layer depths on deciduous recruitment are likely to translate into a prolonged phase of deciduous dominance during post-fire succession in severely burned stands. This shift in vegetation distribution has important implications for climate-albedo feedbacks, future fire regime, wildlife habitat quality and natural resources for indigenous subsistence

Biomass - Overview of Swiss Research Programme 2003; Biomasse

Energy Technology Data Exchange (ETDEWEB)

Binggeli, D.; Guggisberg, B.

2003-07-01

This overview for the Swiss Federal Office of Energy (SFOE) discusses the results obtained in 2003 in various research projects worked on in Switzerland on the subject of biomass. In the biomass combustion area, subjects discussed include system optimisation for automatic firing, combustion particles, low-particle pellet furnaces, design and optimisation of wood-fired storage ovens, efficiency of filtering techniques and methane generation from wood. Also, an accredited testing centre for wood furnaces is mentioned and measurements made on an installation are presented. As far as the fermentation of biogenic wastes is concerned, biogas production from dairy-product wastes is described. Other projects discussed include a study on eco-balances of energy products, certification and marketing of biogas, evaluation of membranes, a measurement campaign for solar sludge-drying, the operation of a percolator installation for the treatment of bio-wastes, the effects of compost on the environment and the fermentation of coffee wastes. Also, statistics on biogas production in 2002 is looked at. Finally, a preliminary study on biofuels is presented.

Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler

Energy Technology Data Exchange (ETDEWEB)

Brostroem, Markus; Backman, Rainer; Nordin, Anders [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden); Kassman, Haakan [Vattenfall Power Consultant AB, Box 1046, SE-611 29 Nykoeping (Sweden); Helgesson, Anna; Berg, Magnus; Andersson, Christer [Vattenfall Research and Development AB, SE-814 26 Aelvkarleby (Sweden)

2007-12-15

Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as ''ChlorOut''. IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW{sub th}/25MW{sub e} circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (author)

Severe fire weather and intensive forest management increase fire severity in a multi-ownership landscape.

Science.gov (United States)

Zald, Harold S J; Dunn, Christopher J

2018-04-26

Many studies have examined how fuels, topography, climate, and fire weather influence fire severity. Less is known about how different forest management practices influence fire severity in multi-owner landscapes, despite costly and controversial suppression of wildfires that do not acknowledge ownership boundaries. In 2013, the Douglas Complex burned over 19,000 ha of Oregon & California Railroad (O&C) lands in Southwestern Oregon, USA. O&C lands are composed of a checkerboard of private industrial and federal forestland (Bureau of Land Management, BLM) with contrasting management objectives, providing a unique experimental landscape to understand how different management practices influence wildfire severity. Leveraging Landsat based estimates of fire severity (Relative differenced Normalized Burn Ratio, RdNBR) and geospatial data on fire progression, weather, topography, pre-fire forest conditions, and land ownership, we asked (1) what is the relative importance of different variables driving fire severity, and (2) is intensive plantation forestry associated with higher fire severity? Using Random Forest ensemble machine learning, we found daily fire weather was the most important predictor of fire severity, followed by stand age and ownership, followed by topographic features. Estimates of pre-fire forest biomass were not an important predictor of fire severity. Adjusting for all other predictor variables in a general least squares model incorporating spatial autocorrelation, mean predicted RdNBR was higher on private industrial forests (RdNBR 521.85 ± 18.67 [mean ± SE]) vs. BLM forests (398.87 ± 18.23) with a much greater proportion of older forests. Our findings suggest intensive plantation forestry characterized by young forests and spatially homogenized fuels, rather than pre-fire biomass, were significant drivers of wildfire severity. This has implications for perceptions of wildfire risk, shared fire management responsibilities, and developing

Nitrogen balance along a northern boreal forest fire chronosequence.

Science.gov (United States)

Palviainen, Marjo; Pumpanen, Jukka; Berninger, Frank; Ritala, Kaisa; Duan, Baoli; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

2017-01-01

Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests.

Fire in Fennoscandia: A palaeo-perspective of spatial and temporal variability in fire frequency and vegetation dynamics

Science.gov (United States)

Clear, Jennifer; Bradshaw, Richard; Seppä, Heikki

2014-05-01

Active fire suppression in Fennoscandia has created a boreal forest ecosystem that is almost free of fire. Absence of fire is thought to have contributed to the widespread dominance of Picea abies (Norway spruce), though the character and structure of spruce forests operates as a positive feedback retarding fire frequency. This lack of fire and dominance by Picea abies may have assisted declines in deciduous tree species, with a concomitant loss of floristic diversity. Forest fires are driven by a complex interplay between natural (climate, vegetation and topography) and anthropogenic disturbance and through palaeoecology we are able to explore spatio-temporal variability in the drivers of fire, changing fire dynamics and the subsequent consequences for forest succession, development and floristic diversity over long timescales. High resolution analysis of palaeoenvironmental proxies (pollen and macroscopic charcoal) allows Holocene vegetation and fire dynamics to be reconstructed at the local forest-stand scale. Comparisons of fire histories with pollen-derived quantitative reconstruction of vegetation at local- and regional-scales identify large-scale ecosystem responses and local-scale disturbance. Spatio-temporal heterogeneity and variability in biomass burning is explored to identify the drivers of fire and palaeovegetation 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. Fire was not always so infrequent in the northern European forest with early-Holocene fire regimes driven by natural climate variations and fuel availability. The establishment and spread of Picea abies was probably driven by an increase in continentality of climate, but local natural and anthropogenic ecosystem disturbance may have aided this spread. Picea expansion led to a step-wise reduction in regional biomass burning and here we show the now

Forest wildfire increases soil microbial biomass C:N:P stoichiometry in long-term effects

Science.gov (United States)

Zhou, Xuan

2017-04-01

Boreal forest fire strongly influences carbon (C) stock in permafrost soil by thawing permafrost table which accelerated microbe decomposition process. We studied soil microbial biomass stoichiometry in a gradient of four (3 yr, 25 yr, 46 yr and more than 100 yr) ages since fire in Canada boreal forest. Soil microbial biomass (MB) in long-term after fire is significantly higher than in short-term. MB C and nitrogen (N) were mainly dominated by corresponding soil element concentration and inorganic P, while MB phosphorus (P) changes were fully explained by soil N. Fire ages and soil temperature positively increased MB N and P, indicating the negative impact by fire. Microbial C:N:P gradually increased with fire ages from 15:2:1 to 76:6:1 and then drop down to 17:2:1 in the oldest fire ages. The degree of homeostasis of microbial C, N and P are close to 1 indicates non-homoeostasis within microbial elements, while it of C:N:P is close to 8 shows a strong homeostasis within element ratios and proved microbial stoichiometric ratio is not driven by soil element ratios. In conclusion, i) microbial biomass elements highly depends on soil nutrient supply rather than fire ages; ii) wildfire decreased microbial stoichiometry immediate after fire but increased with years after fire (YF) which at least 3 times higher than > 100 fire ages; iii) microbial biomass C, N and P deviated from strict homeostasis but C:N:P ratio reflects stronger homeostasis.

Biomass power in transition

Energy Technology Data Exchange (ETDEWEB)

Marshall, D.K. [Zurn/NEPCO, Redmond, WA (United States)

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.

Biomass burning fuel consumption rates: a field measurement database

NARCIS (Netherlands)

van Leeuwen, T.T.; van der Werf, G.R.; Hoffmann, A.A.; Detmers, R.G.; Ruecker, G.; French, N.H.F.; Archibald, S.; Carvalho Jr., J.A.; Cook, G.D.; de Groot, J.W.; Hely, C.; Kasischke, E.S.; Kloster, S.; McCarty, J.L.; Pettinari, M.L.; Savadogo, P.

2014-01-01

Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. Fuel consumption (FC) depends on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions.

Temporal species richness-biomass relationships along successional gradients

Science.gov (United States)

Guo, Q.

2003-01-01

Diversity-biomass relationships are frequently reported to be hump-shaped over space at a given time. However, it is not yet clear how diversity and biomass change simultaneously and how they are related to each other over time (e.g. in succession) at one locality. This study develops a temporal model based on the projected changes of various community variables in a generalized terrestrial environment after fire and uses post-fire succession data on Santa Monica Mountains of southern California and other published succession data to examine the temporal diversity-biomass relationships. The results indicate that in the early stages of succession, both diversity and biomass increase and a positive relationship appears, while in the late stages of succession, biomass continued to increase but diversity usually declines; thus a negative relationship may be observed. When the scales of measurement become sufficiently large so that the measured diversity and biomass cross various stages of succession, a 'hump-shaped' relationship can emerge. The diversity-biomass relationship appears to be concordant in space and time when appropriate scales are used. Formerly proposed explanations for spatial patterns may well apply to the temporal patterns (particularly colonization, facilitation and competitive exclusion).

Point-by-point written fiber-Bragg gratings and their application in complex grating designs.

Science.gov (United States)

Marshall, Graham D; Williams, Robert J; Jovanovic, Nemanja; Steel, M J; Withford, Michael J

2010-09-13

The point-by-point technique of fabricating fibre-Bragg gratings using an ultrafast laser enables complete control of the position of each index modification that comprises the grating. By tailoring the local phase, amplitude and spacing of the grating's refractive index modulations it is possible to create gratings with complex transmission and reflection spectra. We report a series of grating structures that were realized by exploiting these flexibilities. Such structures include gratings with controlled bandwidth, and amplitude- and phase-modulated sampled (or superstructured) gratings. A model based on coupled-mode theory provides important insights into the manufacture of such gratings. Our approach offers a quick and easy method of producing complex, non-uniform grating structures in both fibres and other mono-mode waveguiding structures.

NOx emissions and thermal efficiencies of small scale biomass-fuelled combustion plant with reference to process industries in a developing country

International Nuclear Information System (INIS)

Tariq, A.S.; Purvis, M.R.I.

1996-01-01

Solid biomass materials are an important industrial fuel in many developing countries and also show good potential for usage in Europe within a future mix of renewable energy resources. The sustainable use of wood fuels for combustion relies on operation of plant with acceptable thermal efficiency. There is a clear link between plant efficiency and environmental impacts due to air pollution and deforestation. To supplement a somewhat sparse literature on thermal efficiencies and nitrogen oxide emissions from biomass-fuelled plants in developing countries, this paper presents results for tests carried out on 14 combustion units obtained during field trials in Sri Lanka. The plants tested comprised steam boilers and process air heaters. Biomass fuels included: rubber-wood, fuelwood from natural forests; coconut shells; rice husks; and sugar can bagasse. Average NO x (NO and NO 2 ) emissions for the plants were found to be 47 gNO 2 GJ -1 with 18% conversion of fuel nitrogen. The former value is the range of NO x emission values quoted for combustion of coal in grate-fired systems; some oil-fired systems and systems operating on natural gas, but is less than the emission levels for the combustion of pulverized fuel and heavy fuel oil. This value is significantly within current European standards for NO x emission from large combustion plants. Average thermal efficiency of the plants was found to be 50%. Observations made on operational practices demonstrated that there is considerable scope for the improvement of this thermal efficiency value by plant supervisor training, drying of fuelwood and the use of simple instruments for monitoring plant performance. (Author)

Green power production by co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGCC processes

Energy Technology Data Exchange (ETDEWEB)

Van Ree, R; Korbee, R; De Smidt, R P; Jansen, D [ECN Fuels Conversion and Environment, Petten (Netherlands); Baumann, H R; Ullrich, N [Krupp Uhde, Dortmund (Germany); Haupt, G; Zimmerman, [Siemens, Erlangen (Germany)

1998-11-01

The use of coal for large scale power production meets a growing environmental concern. In spite of the fact that clean coal conversion technologies integrated with high-efficiency power production facilities, such as IGCC, are developed, the aim for sustainable development strives for a power production system based on renewable energy sources. One of the most promising renewable energy sources that can be used in the Netherlands is biomass, i.e. organic waste materials and/or energy crops. To accelerate the introduction of this material, in a technical and economically acceptable way, co-gasification with fossil fuels, in particular coal, in large scale IGCC processes is considered. In this paper the technical feasibility, economic profitability, and environmental acceptability of co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGM is discussed. Both a base-case coal-fired oxygen-blown entrained-flow based IGCC process - showing strong resemblance to the Puertollano IGCC plant in Spain - and three co-gasification concepts, viz.: (1) a concept with separate dry coal and biomass feeding systems, (2) a concept with a combined dry coal/biomass-derived pyrolysis char feeding system, and (3) a concept with parallel biomass pre-treatment/gasification and combined fuel gas clean-up/power production, were defined for further consideration. The base-case system and the co-gasification concepts as well are modelled in the flowsheet simulation package ASPEN{sup +}. Steady-state integral system calculations resulted in an overall net electrical plant efficiency for the base-case system of 50. 1 %LHV (48.3 %HHV). Replacing about 10 % of the total thermal plant input (coal) by biomass (willow) resulted in a decrease of the overall net electrical plant efficiency of 1.4 to 2.1 %-points LHV, avoided specific CO2 emissions of 40-49 g/kWh{sub e}, and total avoided CO2 emissions of about 129 to 159 kt/a, all depending on the co-gasification concept

Annual and diurnal african biomass burning temporal dynamics

Directory of Open Access Journals (Sweden)

G. Roberts

2009-05-01

Full Text Available Africa is the single largest continental source of biomass burning emissions. Here we conduct the first analysis of one full year of geostationary active fire detections and fire radiative power data recorded over Africa at 15-min temporal interval and a 3 km sub-satellite spatial resolution by the Spinning Enhanced Visible and Infrared Imager (SEVIRI imaging radiometer onboard the Meteosat-8 satellite. We use these data to provide new insights into the rates and totals of open biomass burning over Africa, particularly into the extremely strong seasonal and diurnal cycles that exist across the continent. We estimate peak daily biomass combustion totals to be 9 and 6 million tonnes of fuel per day in the northern and southern hemispheres respectively, and total fuel consumption between February 2004 and January 2005 is estimated to be at least 855 million tonnes. Analysis is carried out with regard to fire pixel temporal persistence, and we note that the majority of African fires are detected only once in consecutive 15 min imaging slots. An investigation of the variability of the diurnal fire cycle is carried out with respect to 20 different land cover types, and whilst differences are noted between land covers, the fire diurnal cycle characteristics for most land cover type are very similar in both African hemispheres. We compare the Fire Radiative Power (FRP derived biomass combustion estimates to burned-areas, both at the scale of individual fires and over the entire continent at a 1-degree scale. Fuel consumption estimates are found to be less than 2 kg/m² for all land cover types noted to be subject to significant fire activity, and for savanna grasslands where literature values are commonly reported the FRP-derived median fuel consumption estimate of 300 g/m² is well within commonly quoted values. Meteosat-derived FRP data of the type presented here is now available freely to interested users continuously and in near

Fire, Climate, and Human Activity: A Combustive Combination

Science.gov (United States)

Kehrwald, N. M.; Battistel, D.; Argiriadis, E.; Barbante, C.; Barber, L. B.; Fortner, S. K.; Jasmann, J.; Kirchgeorg, T.; Zennaro, P.

2017-12-01

Ice and lake core records demonstrate that fires caused by human activity can dominate regional biomass burning records in the Common Era. These major increases in fires are often associated with extensive land use change such as an expansion in agriculture. Regions with few humans, relatively stable human populations and/or unvarying land use often have fire histories that are dominated by climate parameters such as temperature and precipitation. Here, we examine biomass burning recorded in ice cores from northern Greenland (NEEM, (77°27'N; 51°3.6'W), Alaska (Juneau Icefield, 58° 35' N; 134° 29'W) and East Antarctica (EPICA DOME C; 75°06'S; 123°21'E), along with New Zealand lake cores to investigate interactions between climate, fire and human activity. Biomarkers such as levoglucosan, and its isomers mannosan and galactosan, can only be produced by cellulose combustion and therefore are specific indicators of past fire activity archived in ice and lake cores. These fire histories add another factor to climate proxies from the same core, and provide a comparison to regional fire syntheses from charcoal records and climate models. For example, fire data from the JSBACH-Spitfire model for the past 2000 years demonstrates that a climate-only scenario would not increase biomass burning in high northern latitudes for the past 2000 years, while NEEM ice core and regional pollen records demonstrate both increased fire activity and land use change that may be ascribed to human activity. Additional biomarkers such as fecal sterols in lake sediments can determine when people were in an area, and can help establish if an increased human presence in an area corresponds with intensified fire activity. This combination of specific biomarkers, other proxy data, and model output can help determine the relative impact of humans versus climate factors on regional fire activity.

Wood biomass : fuel for wildfires or feedstock for bioenergy ?

Energy Technology Data Exchange (ETDEWEB)

Miller, C.S. [Miller Dewulf Corp., Studio City, CA (United States)

2007-07-01

The clean conversion of woody biomass-to-energy has been touted as an alternative to fossil fuel energy and as a solution to environmental challenges. This presentation discussed the state of forest health in North America with particular reference to the higher incidence of megafires, such as recent fires in Colorado, San Diego, Lake Arrowhead, Lake Tahoe, Zaca, and Okefenokee. Federal authorities have an increased responsibility to preserve old forest stands; sustain and increase biodiversity; protect habitats; fight fires to protect real estate; and, contain and suppress wildfires. It was noted that while healthy forests absorb greenhouse gases (GHGs), burning forests release them. The Colorado Hayman fire alone emitted more carbon dioxide in one day than all the cars in the United States in one week. It was cautioned that unharvested fire residues contribute 300 per cent more GHG during decay. The problem of forest density was also discussed, noting that many forests on public lands have grown dangerously overcrowded due to a century of fire suppression and decades of restricted timber harvesting. A sustainable solution was proposed in which decaying biomass can be harvested in order to pay for forest management. Other solutions involve reforesting to historic models and mechanically thinning vulnerable forests for bioenergy. In California's Eagle Lake Ranger District, there are 8 stand-alone wood fired power plants with 171 MWh generating capacity. In addition, there are 5 small log sawmills with cogeneration facilities. A review of feedstock for bioenergy was also included in this presentation, along with an ethanol feedstock comparison of corn and woody biomass. Technologies to produce biofuels from biomass were also reviewed with reference to traditional conversion using sugar fermentation as well as biochemical enzymatic acid hydrolysis. It was concluded that woody biomass stores abundant energy that can be used to create heat, produce steam and

Human impacts on fire occurrence: a case study of hundred years of forest fires in a dry alpine valley in Switzerland

NARCIS (Netherlands)

Zumbrunnen, T.; Menéndez, P.; Bugmann, H.; Conedera, M.; Gimmi, U.; Bürgi, M.

2012-01-01

Forest fire regimes are sensitive to alterations of climate, fuel load, and ignition sources. We investigated the impact of human activities and climate on fire occurrence in a dry continental valley of the Swiss Alps (Valais) by relating fire occurrence to population and road density, biomass

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

Institute of Scientific and Technical Information of China (English)

2007-01-01

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

Spherical grating spectrometers

Science.gov (United States)

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.

Successful experience with limestone and other sorbents for combustion of biomass in fluid bed power boilers

Energy Technology Data Exchange (ETDEWEB)

Coe, D.R. [LG& E Power Systems, Inc., Irvine, CA (United States)

1993-12-31

This paper presents the theoretical and practical advantages of utilizing limestone and other sorbents during the combustion of various biomass fuels for the reduction of corrosion and erosion of boiler fireside tubing and refractory. Successful experiences using a small amount of limestone, dolomite, kaolin, or custom blends of aluminum and magnesium compounds in fluid bed boilers fired with biomass fuels will be discussed. Electric power boiler firing experience includes bubbling bed boilers as well as circulating fluid bed boilers in commercial service on biomass fuels. Forest sources of biomass fuels fired include wood chips, brush chips, sawmill waste wood, bark, and hog fuel. Agricultural sources of biomass fuels fired include grape vine prunings, bean straw, almond tree chips, walnut tree chips, and a variety of other agricultural waste fuels. Additionally, some urban sources of wood fuels have been commercially burned with the addition of limestone. Data presented includes qualitative and quantitative analyses of fuel, sorbent, and ash.

Impacts of Frequent Burning on Live Tree Carbon Biomass and Demography in Post-Harvest Regrowth Forest

Directory of Open Access Journals (Sweden)

Luke Collins

2014-04-01

Full Text Available The management of forest ecosystems to increase carbon storage is a global concern. Fire frequency has the potential to shift considerably in the future. These shifts may alter demographic processes and growth of tree species, and consequently carbon storage in forests. Examination of the sensitivity of forest carbon to the potential upper and lower extremes of fire frequency will provide crucial insight into the magnitude of possible change in carbon stocks associated with shifts in fire frequency. This study examines how tree biomass and demography of a eucalypt forest regenerating after harvest is affected by two experimentally manipulated extremes in fire frequency (i.e., ~3 year fire intervals vs. unburnt sustained over a 23 year period. The rate of post-harvest biomass recovery of overstorey tree species, which constituted ~90% of total living tree biomass, was lower within frequently burnt plots than unburnt plots, resulting in approximately 20% lower biomass in frequently burnt plots by the end of the study. Significant differences in carbon biomass between the two extremes in frequency were only evident after >15–20 years of sustained treatment. Reduced growth rates and survivorship of smaller trees on the frequently burnt plots compared to unburnt plots appeared to be driving these patterns. The biomass of understorey trees, which constituted ~10% of total living tree biomass, was not affected by frequent burning. These findings suggest that future shifts toward more frequent fire will potentially result in considerable reductions in carbon sequestration across temperate forest ecosystems in Australia.

Biomass Co-Firing in Suspension-Fired Power Plants

DEFF Research Database (Denmark)

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

, in the future it is expected to become relevant to cofire in more advanced plants as the trend in the power plant structure is towards older plants having fewer operating hours or being decommissioned. A major product of this project is an experimentally validated computational fluid dynamics (CFD) based...... modelling tool adapted to accommodate biomass cofiring combustion features. The CFD tool will be able to predict deposit accumulation, particle conversion, fly ash composition, temperatures, velocities, and composition of furnace gases, etc. The computer model will primarily be used in the development...

Fabrication update on critical-angle transmission gratings for soft x-ray grating spectrometers

Science.gov (United States)

Heilmann, Ralf K.; Bruccoleri, Alex; Mukherjee, Pran; Yam, Jonathan; Schattenburg, Mark L.

2011-09-01

Diffraction grating-based, wavelength dispersive high-resolution soft x-ray spectroscopy of celestial sources promises to reveal crucial data for the study of the Warm-Hot Intergalactic Medium, the Interstellar Medium, warm absorption and outflows in Active Galactic Nuclei, coronal emission from stars, and other areas of interest to the astrophysics community. Our recently developed critical-angle transmission (CAT) gratings combine the advantages of the Chandra high and medium energy transmission gratings (low mass, high tolerance of misalignments and figure errors, polarization insensitivity) with those of blazed reflection gratings (high broad band diffraction efficiency, high resolution through use of higher diffraction orders) such as the ones on XMM-Newton. Extensive instrument and system configuration studies have shown that a CAT grating-based spectrometer is an outstanding instrument capable of delivering resolving power on the order of 5,000 and high effective area, even with a telescope point-spread function on the order of many arc-seconds. We have fabricated freestanding, ultra-high aspect-ratio CAT grating bars from silicon-on-insulator wafers using both wet and dry etch processes. The 200 nm-period grating bars are supported by an integrated Level 1 support mesh, and a coarser external Level 2 support mesh. The resulting grating membrane is mounted to a frame, resulting in a grating facet. Many such facets comprise a grating array that provides light-weight coverage of large-area telescope apertures. Here we present fabrication results on the integration of CAT gratings and the different high-throughput support mesh levels and on membrane-frame bonding. We also summarize recent x-ray data analysis of 3 and 6 micron deep wet-etched CAT grating prototypes.

Boiler conversions for biomass

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

Boiler conversions for biomass

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

Biomass Burning: The Cycling of Gases and Particulates from the Biosphere to the Atmosphere

Science.gov (United States)

Levine, J. S.

2003-12-01

Biomass burning is both a process of geochemical cycling of gases and particulates from the biosphere to the atmosphere and a process of global change. In the preface to the book, One Earth, One Future: Our Changing Global Environment (National Academy of Sciences, 1990), Dr. Frank Press, the President of the National Academy of Sciences, writes: "Human activities are transforming the global environment, and these global changes have many faces: ozone depletion, tropical deforestation, acid deposition, and increased atmospheric concentrations of gases that trap heat and may warm the global climate."It is interesting to note that all four global change "faces" identified by Dr. Press have a common thread - they are all caused by biomass burning.Biomass burning or vegetation burning is the burning of living and dead vegetation and includes human-initiated burning and natural lightning-induced burning. The bulk of the world's biomass burning occurs in the tropics - in the tropical forests of South America and Southeast Asia and in the savannasof Africa and South America. The majority of the biomass burning, primarily in the tropics (perhaps as much as 90%), is believed to be human initiated for land clearing and land-use change. Natural fires triggered by atmospheric lightning only accounts for ˜10% of all fires (Andreae, 1991). As will be discussed, a significant amount of biomass burning occurs in the boreal forests of Russia, Canada, and Alaska.Biomass burning is a significant source of gases and particulates to the regional and global atmosphere (Crutzen et al., 1979; Seiler and Crutzen, 1980; Crutzen and Andreae, 1990; Levine et al., 1995). Its burning is truly a multidiscipline subject, encompassing the following areas: fire ecology, fire measurements, fire modeling, fire combustion, remote sensing, fire combustion gaseous and particulate emissions, the atmospheric transport of these emissions, and the chemical and climatic impacts of these emissions. Recently

Development of low cost systems for co-utilisation of biomass in large power plant. Mid term review report

Energy Technology Data Exchange (ETDEWEB)

Livingston, W.R.

2003-07-01

Interest in the cofiring of biomass materials with coal in large coal-fired power stations in the UK has increased significantly in recent years in response to the potential additional income from Renewables Obligation Certificates (ROCs). It is anticipated that most coal-fired power stations in the UK will have the capability to cofire biomass materials by the end of 2003. This mid-term review report examines the various stages in the route to fully commercial operation of biomass cofiring at coal-fired power stations, the availability of suitable biomass materials in the UK and the technical options for cofiring. The factors affecting the economics of biomass cofiring in large coal-fired boilers are discussed including the delivered price of biofuels, the future value of ROCs, the development costs of cofiring projects, the 25% ceiling on cofiring imposed by the Renewables Obligation Order 2002 and the use of preblending. An overview of the current status of cofiring in the UK is presented, which includes a summary of the results of trials already carried out by operators of coal-fired power stations and a discussion of the future prospects for biomass cofiring in the UK.

Clean and efficient application of biomass for production of power and heat - Phase 3 in a long-term strategic research project

Energy Technology Data Exchange (ETDEWEB)

Frandsen, F.J.; Jensen, A.D.; Jensen, P.A.; Johnsson, J.E.; Dam-Johansen, K.

2002-06-01

This project contains activities on: Rheology of ashes from co-firing of coal and biomass; Investigation of ash and deposit formation in full-scale utility boilers; and Selective catalytic reduction: Deactivation under biomass combustion. A fly ash and deposit investigation was carried out as part of the SK Power Company test programme on co-firing of biomasses in a grate-fired boiler. The alternative biomasses (wood chips, olive stones and shea nuts) contain more K, S, and Cl, than wheat straw, and higher fly ash mass loading (mass of fly ash/volume of flue gas) was observed when co-firing alternative biomasses with wheat straw. Anyhow, no significant change in deposit structure when co-firing alkali-rich biomass was observed: KCl is glues residual ash particles together, independent of the feedstock mixture. Thus it can be concluded that co-firing of the actual biomasses in boilers designed for straw-firing, at the present shares is not problematic, from an ash formation and/or deposit build-up point-of-view. Anyhow the increase in ash mass loading in the flue gas, may cause increased build-up of particulate deposits in the convective pass of the boiler. Mature deposit samples from the Masnedoe and Ensted straw-fired boilers were investigated by SEM and EDX. Each deposit sample was classified into an inner, an intermediate, and an outer main layer. The outermost deposit layers at Masnedoe and Ensted looked chemically quite similar, even though they were of different colours. The intermediate layer at Ensted contained many Si- and Ca-rich particles glued together by melted KCI, while the intermediate deposit layers at Masnedoe were different. Since the straw fuels probably are similar, the differences observed in the deposit chemistry must be induced by the higher temperature of the Masnedoe deposit. An experimental method has been set up for viscosity determinations on ashes from co-firing with wheat straw. The method contains a pre-treatment of the ashes, where

Solid biomass barometer - EurObserv'ER - December 2012

International Nuclear Information System (INIS)

2012-12-01

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

PCDD/F EMISSIONS FROM FOREST FIRE SIMULATIONS

Science.gov (United States)

Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions from combustion of forest biomass were sampled to obtain an estimated emission factor for forest fires. An equal composition of live shoot and litter biomass from Oregon and North Carolina was b...

Fire passage on geomorphic fractures in Cerrado: effect on vegetation

Directory of Open Access Journals (Sweden)

Otacílio Antunes Santana

2017-01-01

Full Text Available Geomorphic fracture is a natural geologic formation that sometimes forms a deep fissure in the rock with the establishment of soil and vegetation. The objective of this work was to analyze vegetation within geomorphic fractures under the effect of wildfire passage. The biometric variables evaluated before and after fire passage were: diameter, height, leaf area index, timber volume, grass biomass, number of trees and shrubs and of species. Results (in fractures were compared to adjacent areas (control. The effect of wildfire passage on vegetation within geomorphic fractures was not significant because fire followed plant biomass bed and when it met the fracture (wetter, it changed from soil surface to canopy surface (jump fire effect, affecting without significance the number of plants or species; so, fracture could be plants refuge against fire passage. We could infer in our experimental model that quality of plant biomass bed could be more significant than quantity, and microclimate variability recruits plants to the refuge (geomorphic fracture.

Feasibility evaluation of a neutron grating interferometer with an analyzer grating based on a structured scintillator

Science.gov (United States)

Kim, Youngju; Kim, Jongyul; Kim, Daeseung; Hussey, Daniel. S.; Lee, Seung Wook

2018-03-01

We introduce an analyzer grating based on a structured scintillator fabricated by a gadolinium oxysulfide powder filling method for a symmetric Talbot-Lau neutron grating interferometer. This is an alternative way to analyze the Talbot self-image of a grating interferometer without using an absorption grating to block neutrons. Since the structured scintillator analyzer grating itself generates the signal for neutron detection, we do not need an additional scintillator screen as an absorption analyzer grating. We have developed and tested an analyzer grating based on a structured scintillator in our symmetric Talbot-Lau neutron grating interferometer to produce high fidelity absorption, differential phase, and dark-field contrast images. The acquired images have been compared to results of a grating interferometer utilizing a typical absorption analyzer grating with two commercial scintillation screens. The analyzer grating based on the structured scintillator enhances interference fringe visibility and shows a great potential for economical fabrication, compact system design, and so on. We report the performance of the analyzer grating based on a structured scintillator and evaluate its feasibility for the neutron grating interferometer.

Foster Wheeler experience with biomass and other CO{sub 2}-neutral fuels in large CFBs

Energy Technology Data Exchange (ETDEWEB)

Zabetta, E.; Kauppinen, K.; Slotte, M. (Foster Wheeler Power Group Europe, Varkaus (Finland)), Email: edgardo.coda@fwfin.fwc.com

2009-07-01

Foster Wheeler is a global engineering and construction contractor and a power equipment supplier. Among other products, the company offers state-of-the-art boilers for heat and electricity generation. During the past 30 years Foster Wheeler has booked over 350 circulating fluidized bed boilers (CFBs) ranging from 7 to nearly 1000 MW{sub th}. Of these, over 50 are designed for biomass (or bio-mix) and nearly 50 for waste (or waste-mix) containing biodegradable fractions, which are considered CO{sub 2}-neutral. The biggest challenges encountered in biomass (co-)firing are the tendency towards bed agglomeration and fouling of convective heat surfaces, often associated to corrosion. Such problems are marginal with certain woody biomass, but they intensify when other biomass or waste are fired, and further grow when boilers must operate at highest efficiency while firing erratic fuel mixtures. This paper describes the designs and tools developed at Foster Wheeler to fire different types of biomass and wastes in large CFB boilers. Latest references are then described, showing the ever growing performances achievable when firing CO{sub 2}-neutral fuels, but also highlighting the challenges of boilers that must maintain high performance throughout unprecedentedly broad fuel ranges. (orig.)

Fiber Optic Bragg Gratings

National Research Council Canada - National Science Library

Battiato, James

1998-01-01

Coupled mode theory was used to model reflection fiber gratings. The effects of experimental parameters on grating characteristics were modeled for both uniform and non-uniform grating profiles using this approach...

Visual obstruction as a method to quantify herbaceous biomass in ...

African Journals Online (AJOL)

Biomass of aboveground vegetation is a useful descriptor for studies of grazing, fire and wildlife habitat use in grassland systems. The traditional method to estimate biomass, hand-clipping, is time intensive and other indices of biomass have been used successfully. In southern Africa, the disc pasture meter has been the ...

Biomass fuel characterization for NOx emissions in cofiring applications

NARCIS (Netherlands)

Di Nola, G.

2007-01-01

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

Solid biomass barometer 2011

International Nuclear Information System (INIS)

2012-01-01

The winter of 2011 was exceptionally mild, even in Northern Europe, with unusually warm temperatures. As a result the demand for firewood and solid biomass fuel was low. The European Union's primary energy production from solid biomass contracted by 2.9% slipping to 78.8 Mtoe. The first 4 countries are Germany (11.690 Mtoe), France (9.223 Mtoe), Sweden (8.165 Mtoe) and Finland (7.476 Mtoe) and when the production is relative to the population the first 4 countries become: Finland (1.391 toe/inhab.), Sweden (0.867 toe/inhab.), Latvia (0.784 toe/inhab.) and Estonia (0.644 toe/inhab.). Solid biomass electricity production continued to grow, driven by the additional take-up of biomass co-firing, to reach 72.800 TWh at the end of 2011, it means +2.6% compared to 2010. The energy policy of various states concerning solid biomass is analyzed

Grating array systems having a plurality of gratings operative in a coherently additive mode and methods for making such grating array systems

Science.gov (United States)

Kessler, Terrance J [Mendon, NY; Bunkenburg, Joachim [Victor, NY; Huang, Hu [Pittsford, NY

2007-02-13

A plurality of gratings (G1, G2) are arranged together with a wavefront sensor, actuators, and feedback system to align the gratings in such a manner, that they operate like a single, large, monolithic grating. Sub-wavelength-scale movements in the mechanical mounting, due to environmental influences, are monitored by an interferometer (28), and compensated by precision actuators (16, 18, 20) that maintain the coherently additive mode. The actuators define the grating plane, and are positioned in response to the wavefronts from the gratings and a reference flat, thus producing the interferogram that contains the alignment information. Movement of the actuators is also in response to a diffraction-limited spot on the CCD (36) to which light diffracted from the gratings is focused. The actuator geometry is implemented to take advantage of the compensating nature of the degrees of freedom between gratings, reducing the number of necessary control variables.

Characterization and quantification of deposits build up and removal in straw suspension fired boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt; Shafique Bashir, Muhammad; Wedel, Stig

This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed by condu......This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed...... by conducting advanced probe measurements at the Amagerværkets Vattenfall owed boilers. It was the objective of the project to provide an improved understanding of ash deposit formation and removal in biomass suspension fired boilers. The project have provided a large amount of knowledge on the following issues......: 1) The influence of local boiler conditions on deposit formation in suspension fired boilers using wood or co-firing straw and wood, 2) quantification of deposit removal in biomass suspension firing boilers with regards both to natural shedding and soot blower induced shedding, 3) established...

Proceedings of the fifth International Slovak Biomass Forum (ISBF)

International Nuclear Information System (INIS)

2005-02-01

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

Controls upon biomass losses and char production from prescribed burning on UK moorland.

Science.gov (United States)

Worrall, Fred; Clay, Gareth D; May, Richard

2013-05-15

Prescribed burning is a common management technique used across many areas of the UK uplands. However, there are few data sets that assess the loss of biomass during burning and even fewer data on the effect of burning on above-ground carbon stocks and production of char. During fire the production of char occurs which represents a transfer of carbon from the short term bio-atmospheric cycle to the longer term geological cycle. However, biomass is consumed leading to the reduction in litter formation which is the principal mechanism for peat formation. This study aims to solve the problem of whether loss of biomass during a fire is ever outweighed by the production of refractory forms of carbon during the fire. This study combines both a laboratory study of char production with an assessment of biomass loss from a series of field burns from moorland in the Peak District, UK. The laboratory results show that there are significant effects due to ambient temperature but the most important control on dry mass loss is the maximum burn temperature. Burn temperature was also found to be linearly related to the production of char in the burn products. Optimisation of dry mass loss, char production and carbon content shows that the production of char from certain fires could store more carbon in the ecosystem than if there had been no fire. Field results show that approximately 75% of the biomass and carbon were lost through combustion, a figure comparable to other studies of prescribed fire in other settings. Char-C production was approximately 2.6% of the carbon consumed during the fire. This study has shown that there are conditions (fast burns at high temperatures) under which prescribed fire may increase C sequestration through char production and that these conditions are within existing management options available to practitioners. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluating the sustainability of co-firing in the UK

Energy Technology Data Exchange (ETDEWEB)

Woods, Jeremy; Tipper, Richard; Brown, Gareth; Diaz-Chavez, Rocio; Lovell, Jessica; de Groot, Peter

2006-10-09

The objectives of the study were: Assess the overall carbon balance for co-firing; Investigate the other sustainability issues relating to co-firing; Assess the scope for incentivising the most sustainable forms of co-firing. The main questions to be addressed were: Is the overall carbon balance for co-firing positive? What is the difference in carbon balance between energy crops and other biomass? Are some kinds of energy crops better than others? How big a factor is transport in the carbon balance? Under what circumstances (fuel, transport, process, etc.) are the greatest benefits of co-firing in terms of carbon balance and sustainability? Are there any circumstances (as above) that could raise serious carbon balance or sustainability issues? How does the carbon balance compare between co-firing, dedicated biomass, and biomass heat? Is there any scope for encouraging the most sustainable forms of co-firing - perhaps through using existing or currently in development accreditation schemes? The report concludes that: Co-firing could be expanded to make a significant and low risk contribution to Government and EU renewable energy policy targets; Real environmental and social benefits could arise from the expansion of co-firing markets, both in the UK and in poor developing countries, given responsible development policy; There is no clear environmental or social case, for an arbitrary cap on the amount of co-firing; Co-firing could expand and enhance clean coal Carbon and Capture and Sequestration (CCS). This report focuses solely on the carbon (GHG) and broader sustainability impacts of co-firing in the UK. It does not include an economic evaluation. It provides an overview of the existing materials being used as feedstocks for co-firing and a summary life-cycle assessment of the GHG balances and sustainability (environmental and social) impacts of the provision and use of those feedstocks. A clear distinction is made between the use of residues and dedicated

Evaluating the sustainability of co-firing in the UK

International Nuclear Information System (INIS)

Woods, Jeremy; Tipper, Richard; Brown, Gareth; Diaz-Chavez, Rocio; Lovell, Jessica; de Groot, Peter

2006-01-01

The objectives of the study were: Assess the overall carbon balance for co-firing; Investigate the other sustainability issues relating to co-firing; Assess the scope for incentivising the most sustainable forms of co-firing. The main questions to be addressed were: Is the overall carbon balance for co-firing positive? What is the difference in carbon balance between energy crops and other biomass? Are some kinds of energy crops better than others? How big a factor is transport in the carbon balance? Under what circumstances (fuel, transport, process, etc.) are the greatest benefits of co-firing in terms of carbon balance and sustainability? Are there any circumstances (as above) that could raise serious carbon balance or sustainability issues? How does the carbon balance compare between co-firing, dedicated biomass, and biomass heat? Is there any scope for encouraging the most sustainable forms of co-firing - perhaps through using existing or currently in development accreditation schemes? The report concludes that: Co-firing could be expanded to make a significant and low risk contribution to Government and EU renewable energy policy targets; Real environmental and social benefits could arise from the expansion of co-firing markets, both in the UK and in poor developing countries, given responsible development policy; There is no clear environmental or social case, for an arbitrary cap on the amount of co-firing; Co-firing could expand and enhance clean coal Carbon and Capture and Sequestration (CCS). This report focuses solely on the carbon (GHG) and broader sustainability impacts of co-firing in the UK. It does not include an economic evaluation. It provides an overview of the existing materials being used as feedstocks for co-firing and a summary life-cycle assessment of the GHG balances and sustainability (environmental and social) impacts of the provision and use of those feedstocks. A clear distinction is made between the use of residues and dedicated

Organic aerosols from biomass burning in Amazonian rain forest and their impact onto the environment

International Nuclear Information System (INIS)

Cecinato, A.; Mabilia, R.; De Castro Vasconcellos, P.

2001-01-01

A field campaign performed in Southern Brazilian Amazonia in 1993 has proved that this region is subjected to fallout of particulated exhausts released by fires of forestal biomass. In fact, organic content of aerosols collected at urban sites located on the border of pluvial forest, about 50 km from fires, was similar to that of biomass burning exhausts. Aerosol composition is indicative of dolous origin of fires. However, organic contents seems to be influenced by two additional sources, i. e. motor vehicle and high vegetation emission. Chemical pattern of organic aerosols released by biomass burning of forest seems to promote occurrence of photochemical smog episodes in that region [it

Electro-optic diffraction grating tuned laser

International Nuclear Information System (INIS)

Hughes, R.S.

1975-01-01

An electro-optic diffraction grating tuned laser comprising a laser medium, output mirror, retro-reflective grating and an electro-optic diffraction grating beam deflector positioned between the laser medium and the reflective diffraction grating is described. An optional angle multiplier may be used between the electro-optic diffraction grating and the reflective grating. (auth)

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

Science.gov (United States)

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

2010-05-01

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

Measurement of trace emissions and combustion characteristics for a mass fire

International Nuclear Information System (INIS)

Susott, R.A.; Ward, D.E.; Babbitt, R.E.; Latham, D.J.

1991-01-01

Results are presented of a continuing study of research that was started in 1988. A new sampling system was designed to provide fire dynamics data from within the fire. This chapter describes the sampling system, the measurements it provided on one biomass fire, and some valuable parameters that can be calculated such as emission factors, combustion efficiency, and rate of fuel consumption. The large prescribed fire in Ontario, Canada, provided a practical test of this package that can be used to assess the application of the monitoring concept to a broad range of biomass fires. Measurements of wind vectors, temperature, and emissions of CO 2 , CO and particulates are reported for a 40-minute period from ignition through the critical period of maximum release of heat to the near extinction of the smoldering combustion phase

Comparative Evaluation of Five Fire Emissions Datasets Using the GEOS-5 Model

Science.gov (United States)

Ichoku, C. M.; Pan, X.; Chin, M.; Bian, H.; Darmenov, A.; Ellison, L.; Kucsera, T. L.; da Silva, A. M., Jr.; Petrenko, M. M.; Wang, J.; Ge, C.; Wiedinmyer, C.

2017-12-01

Wildfires and other types of biomass burning affect most vegetated parts of the globe, contributing 40% of the annual global atmospheric loading of carbonaceous aerosols, as well as significant amounts of numerous trace gases, such as carbon dioxide, carbon monoxide, and methane. Many of these smoke constituents affect the air quality and/or the climate system directly or through their interactions with solar radiation and cloud properties. However, fire emissions are poorly constrained in global and regional models, resulting in high levels of uncertainty in understanding their real impacts. With the advent of satellite remote sensing of fires and burned areas in the last couple of decades, a number of fire emissions products have become available for use in relevant research and applications. In this study, we evaluated five global biomass burning emissions datasets, namely: (1) GFEDv3.1 (Global Fire Emissions Database version 3.1); (2) GFEDv4s (Global Fire Emissions Database version 4 with small fires); (3) FEERv1 (Fire Energetics and Emissions Research version 1.0); (4) QFEDv2.4 (Quick Fire Emissions Dataset version 2.4); and (5) Fire INventory from NCAR (FINN) version 1.5. Overall, the spatial patterns of biomass burning emissions from these inventories are similar, although the magnitudes of the emissions can be noticeably different. The inventories derived using top-down approaches (QFEDv2.4 and FEERv1) are larger than those based on bottom-up approaches. For example, global organic carbon (OC) emissions in 2008 are: QFEDv2.4 (51.93 Tg), FEERv1 (28.48 Tg), FINN v1.5 (19.48 Tg), GFEDv3.1 (15.65 Tg) and GFEDv4s (13.76 Tg); representing a factor of 3.7 difference between the largest and the least. We also used all five biomass-burning emissions datasets to conduct aerosol simulations using the NASA Goddard Earth Observing System Model, Version 5 (GEOS-5), and compared the resulting aerosol optical depth (AOD) output to the corresponding retrievals from MODIS

High-accuracy measurement and compensation of grating line-density error in a tiled-grating compressor

Science.gov (United States)

Zhao, Dan; Wang, Xiao; Mu, Jie; Li, Zhilin; Zuo, Yanlei; Zhou, Song; Zhou, Kainan; Zeng, Xiaoming; Su, Jingqin; Zhu, Qihua

2017-02-01

The grating tiling technology is one of the most effective means to increase the aperture of the gratings. The line-density error (LDE) between sub-gratings will degrade the performance of the tiling gratings, high accuracy measurement and compensation of the LDE are of significance to improve the output pulses characteristics of the tiled-grating compressor. In this paper, the influence of LDE on the output pulses of the tiled-grating compressor is quantitatively analyzed by means of numerical simulation, the output beams drift and output pulses broadening resulting from the LDE are presented. Based on the numerical results we propose a compensation method to reduce the degradations of the tiled grating compressor by applying angular tilt error and longitudinal piston error at the same time. Moreover, a monitoring system is setup to measure the LDE between sub-gratings accurately and the dispersion variation due to the LDE is also demonstrated based on spatial-spectral interference. In this way, we can realize high-accuracy measurement and compensation of the LDE, and this would provide an efficient way to guide the adjustment of the tiling gratings.

Evaluation of the FEERv1.0 Global Top-Down Biomass Burning Emissions Inventory over Africa

Science.gov (United States)

Ellison, L.; Ichoku, C. M.

2014-12-01

With the advent of the Fire Energetics and Emissions Research (FEER) global top-down biomass burning emissions product from NASA Goddard Space Flight Center, a subsequent effort is going on to analyze and evaluate some of the main (particulate and gaseous) constituents of this emissions inventory against other inventories of biomass burning emissions over the African continent. There is consistent and continual burning during the dry season in NSSA of many small slash-and-burn fires that, though may be relatively small fires individually, collectively contribute 20-25% of the global total carbon emissions from biomass burning. As a top-down method of estimating biomass-burning emissions, FEERv1.0 is able to yield higher and more realistic emissions than previously obtainable using bottom-up methods. Results of such comparisons performed in detail over Africa will be discussed in this presentation. This effort is carried out in conjunction with a NASA-funded interdisciplinary research project investigating the effects of biomass burning on the regional climate system in Northern Sub-Saharan Africa (NSSA). Essentially, that project aims to determine how fires may have affected the severe droughts that plagued the NSSA region in recent history. Therefore, it is imperative that the biomass burning emissions input data over Africa be as accurate as possible in order to obtain a confident understanding of their interactions and feedbacks with the hydrological cycle in NSSA.

Improved biomass Injera stove- Mirte

International Nuclear Information System (INIS)

Bess, M.; Kenna, J.

1994-01-01

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

Research, Development and Demonstration of Bio-Mass Boiler for Food Industry

Energy Technology Data Exchange (ETDEWEB)

Fisher, Steve [Burns & McDonnell, Inc., Kansas City, MO (United States); Knapp, David [Burns & McDonnell, Inc., Kansas City, MO (United States)

2012-07-01

Frito-Lay is working to reduce carbon emissions from their manufacturing plants. As part of this effort, they invested in a biomass-fired boiler at the Topeka, Kansas, plant. Frito-Lay partnered with Burns & McDonnell Engineering, Inc. and CPL Systems, Inc., to design and construct a steam producing boiler using carbon neutral fuels such as wood wastes (e.g. tree bark), shipping pallets, and used rubber vehicle tires. The U.S. Department of Energy (DOE) joined with Frito-Lay, Burns & McDonnell, and CPL to analyze the reductions in carbon dioxide (CO₂) emissions that result from use of biomass-fired boilers in the food manufacturing environment. DOE support provided for the data collection and analysis, and reporting necessary to evaluate boiler efficiencies and reductions in CO₂ emissions. The Frito-Lay biomass-fired boiler has resulted in significant reductions in CO₂ emissions from the Topeka production facility. The use of natural gas has been reduced by 400 to 420 million standard cubic feet per year with corresponding reductions of 24,000 to 25,000 tons of CO₂. The boiler does require auxiliary functions, however, that are unnecessary for a gas-fired boiler. These include heavy motors and fans for moving fuel and firing the boiler, trucks and equipment for delivering the fuel and moving at the boiler plant, and chippers for preparing the fuel prior to delivery. Each of these operations requires the combustion of fossil fuels or electricity and has associated CO₂ emissions. Even after accounting for each of these auxiliary processes, however, the biomass-fired boiler results in net emission reductions of 22,500 to 23,500 tons of CO₂ per year.

Mitigating Satellite-Based Fire Sampling Limitations in Deriving Biomass Burning Emission Rates: Application to WRF-Chem Model Over the Northern sub-Saharan African Region

Science.gov (United States)

Wang, Jun; Yue, Yun; Wang, Yi; Ichoku, Charles; Ellison, Luke; Zeng, Jing

2018-01-01

Largely used in several independent estimates of fire emissions, fire products based on MODIS sensors aboard the Terra and Aqua polar-orbiting satellites have a number of inherent limitations, including (a) inability to detect fires below clouds, (b) significant decrease of detection sensitivity at the edge of scan where pixel sizes are much larger than at nadir, and (c) gaps between adjacent swaths in tropical regions. To remedy these limitations, an empirical method is developed here and applied to correct fire emission estimates based on MODIS pixel level fire radiative power measurements and emission coefficients from the Fire Energetics and Emissions Research (FEER) biomass burning emission inventory. The analysis was performed for January 2010 over the northern sub-Saharan African region. Simulations from WRF-Chem model using original and adjusted emissions are compared with the aerosol optical depth (AOD) products from MODIS and AERONET as well as aerosol vertical profile from CALIOP data. The comparison confirmed an 30-50% improvement in the model simulation performance (in terms of correlation, bias, and spatial pattern of AOD with respect to observations) by the adjusted emissions that not only increases the original emission amount by a factor of two but also results in the spatially continuous estimates of instantaneous fire emissions at daily time scales. Such improvement cannot be achieved by simply scaling the original emission across the study domain. Even with this improvement, a factor of two underestimations still exists in the modeled AOD, which is within the current global fire emissions uncertainty envelope.

Red imported fire ant impacts on upland arthropods in Southern Mississippi

Science.gov (United States)

Epperson, D.M.; Allen, Craig R.

2010-01-01

Red imported fire ants (Solenopsis invicta) have negative impacts on a broad array of invertebrate species. We investigated the impacts of fire ants on the upland arthropod community on 20???40 ha study sites in southern Mississippi. Study sites were sampled from 19972000 before, during, and after fire ant bait treatments to reduce fire ant populations. Fire ant abundance was assessed with bait transects on all sites, and fire ant population indices were estimated on a subset of study sites. Species richness and diversity of other ant species was also assessed from bait transects. Insect biomass and diversity was determined from light trap samples. Following treatments, fire ant abundance and population indices were significantly reduced, and ant species diversity and richness were greater on treated sites. Arthropod biomass, species diversity and species richness estimated from light trap samples were negatively correlated with fire ant abundance, but there were no observable treatment effects. Solenopsis invicta has the potential to negatively impact native arthropod communities resulting in a potential loss of both species and function.

Experimental investigation and mathematical modelling of wood combustion in a moving grate boiler

International Nuclear Information System (INIS)

Zhang, Xiaohui; Chen, Qun; Sharifi, Vida; Swithenbank, Jim; Bradford, Richard

2010-01-01

The use of biomass to generate energy offers significant environmental advantages for the reduction in emissions of greenhouse gases. The main objective of this study was to investigate the performance of a small scale biomass heating plant: i.e. combustion characteristics and emissions. An extensive series of experimental tests was carried out at a small scale residential biomass heating plant i.e. wood chip fired boiler. The concentrations of CO, NO x , particulate matter in the flue gas were measured. In addition, mathematical modelling work using FLIC and FLUENT codes was carried out in order to simulate the overall performance of the wood fired heating system. Results showed that pollutant emissions from the boiler were within the relative emission limits. Mass concentration of CO emission was 550-1600 mg/m 3 (10% O 2 ). NO x concentration in the flue gas from the wood chips combustion varied slightly between 28 and 60 ppmv. Mass concentration of PM 10 in the flue gas was 205 mg/m 3 (10% O 2 ) The modelling results showed that most of the fuel was burnt inside the furnace and little CO was released from the system due to the high flue gas temperature in the furnace. The injection of the secondary air provided adequate mixing and favourable combustion conditions in the over-bed chamber in the wood chips fired boiler. This study has shown that the use of wood heating system result in much lower CO 2 emissions than from a fossil fuel e.g. coal fired heating system. (author)

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

Science.gov (United States)

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

2010-01-01

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

Biomass Burning: Major Uncertainties, Advances, and Opportunities

Science.gov (United States)

Yokelson, R. J.; Stockwell, C.; Veres, P. R.; Hatch, L. E.; Barsanti, K. C.; Liu, X.; Huey, L. G.; Ryerson, T. B.; Dibb, J. E.; Wisthaler, A.; Müller, M.; Alvarado, M. J.; Kreidenweis, S. M.; Robinson, A. L.; Toon, O. B.; Peischl, J.; Pollack, I. B.

2014-12-01

Domestic and open biomass burning are poorly-understood, major influences on Earth's atmosphere composed of countless individual fires that (along with their products) are difficult to quantify spatially and temporally. Each fire is a minimally-controlled complex phenomenon producing a diverse suite of gases and aerosols that experience many different atmospheric processing scenarios. New lab, airborne, and space-based observations along with model and algorithm development are significantly improving our knowledge of biomass burning. Several campaigns provided new detailed emissions profiles for previously undersampled fire types; including wildfires, cooking fires, peat fires, and agricultural burning; which may increase in importance with climate change and rising population. Multiple campaigns have better characterized black and brown carbon and used new instruments such as high resolution PTR-TOF-MS and 2D-GC/TOF-MS to improve quantification of semi-volatile precursors to aerosol and ozone. The aerosol evolution and formation of PAN and ozone, within hours after emission, have now been measured extensively. The NASA DC-8 sampled smoke before and after cloud-processing in two campaigns. The DC-8 performed continuous intensive sampling of a wildfire plume from the source in California to Canada probing multi-day aerosol and trace gas aging. Night-time plume chemistry has now been measured in detail. Fire inventories are being compared and improved, as is modeling of mass transfer between phases and sub-grid photochemistry for global models.

[Emission characteristics of PM10 from coal-fired industrial boiler].

Science.gov (United States)

Li, Chao; Li, Xing-Hua; Duan, Lei; Zhao, Meng; Duan, Jing-Chun; Hao, Ji-Ming

2009-03-15

Through ELPI (electrical low-pressure impactor) based dilution sampling system, the emission characteristics of PM10 and PM2.5 was studied experimentally at the inlet and outlet of dust catchers at eight different coal-fired industrial boilers. Results showed that a peak existed at around 0.12-0.20 microm of particle size for both number size distribution and mass size distribution of PM10 emitted from most of the boilers. Chemical composition analysis indicated that PM2.5 was largely composed of organic carbon, elementary carbon, and sulfate, with mass fraction of 3.7%-21.4%, 4.2%-24.6%, and 1.5%-55.2% respectively. Emission factors of PM10 and PM2.5 measured were 0.13-0.65 kg x t(-1) and 0.08-0.49 kg x t(-1) respectively for grate boiler using raw coal, and 0.24 kg x t(-1) and 0.22 kg x t(-1) for chain-grate boiler using briquette. In comparison, the PM2.5 emission factor of fluidized bed boiler is 1.14 kg x t(-1), much her than that of grate boiler. Due to high coal consumption and low efficiency of dust separator, coal-fired industrial boiler may become the most important source of PM10, and should be preferentially controlled in China.

Improving satellite retrievals of NO2 in biomass burning regions

Science.gov (United States)

Bousserez, N.; Martin, R. V.; Lamsal, L. N.; Mao, J.; Cohen, R. C.; Anderson, B. E.

2010-12-01

The quality of space-based nitrogen dioxide (NO2) retrievals from solar backscatter depends on a priori knowledge of the NO2 profile shape as well as the effects of atmospheric scattering. These effects are characterized by the air mass factor (AMF) calculation. Calculation of the AMF combines a radiative transfer calculation together with a priori information about aerosols and about NO2 profiles (shape factors), which are usually taken from a chemical transport model. In this work we assess the impact of biomass burning emissions on the AMF using the LIDORT radiative transfer model and a GEOS-Chem simulation based on a daily fire emissions inventory (FLAMBE). We evaluate the GEOS-Chem aerosol optical properties and NO2 shape factors using in situ data from the ARCTAS summer 2008 (North America) and DABEX winter 2006 (western Africa) experiments. Sensitivity studies are conducted to assess the impact of biomass burning on the aerosols and the NO2 shape factors used in the AMF calculation. The mean aerosol correction over boreal fires is negligible (+3%), in contrast with a large reduction (-18%) over African savanna fires. The change in sign and magnitude over boreal forest and savanna fires appears to be driven by the shielding effects that arise from the greater biomass burning aerosol optical thickness (AOT) above the African biomass burning NO2. In agreement with previous work, the single scattering albedo (SSA) also affects the aerosol correction. We further investigated the effect of clouds on the aerosol correction. For a fixed AOT, the aerosol correction can increase from 20% to 50% when cloud fraction increases from 0 to 30%. Over both boreal and savanna fires, the greatest impact on the AMF is from the fire-induced change in the NO2 profile (shape factor correction), that decreases the AMF by 38% over the boreal fires and by 62% of the savanna fires. Combining the aerosol and shape factor corrections together results in small differences compared to the

Near-field emission profiling of tropical forest and Cerrado fires in Brazil during SAMBBA 2012

Science.gov (United States)

Hodgson, Amy K.; Morgan, William T.; O'Shea, Sebastian; Bauguitte, Stéphane; Allan, James D.; Darbyshire, Eoghan; Flynn, Michael J.; Liu, Dantong; Lee, James; Johnson, Ben; Haywood, Jim M.; Longo, Karla M.; Artaxo, Paulo E.; Coe, Hugh

2018-04-01

We profile trace gas and particulate emissions from near-field airborne measurements of discrete smoke plumes in Brazil during the 2012 biomass burning season. The South American Biomass Burning Analysis (SAMBBA) Project conducted during September and October 2012 sampled across two distinct fire regimes prevalent in the Amazon Basin. Combined measurements from a Compact Time-of-Flight Aerosol Mass Spectrometer (C-ToF-AMS) and a Single Particle Soot Photometer (SP2) are reported for the first time in a tropical biomass burning environment. Emissions from a mostly smouldering tropical forest wildfire in Rondônia state and numerous smaller flaming Cerrado fires in Tocantins state are presented. While the Cerrado fires appear to be representative of typical fire conditions in the existing literature, the tropical forest wildfire likely represents a more extreme example of biomass burning with a bias towards mostly smouldering emissions. We determined fire-integrated modified combustion efficiencies, emission ratios and emission factors for trace gas and particulate components for these two fire types, alongside aerosol microphysical properties. Seven times more black carbon was emitted from the Cerrado fires per unit of fuel combustion (EFBC of 0.13 ± 0.04 g kg-1) compared to the tropical forest fire (EFBC of 0.019 ± 0.006 g kg-1), and more than 6 times the amount of organic aerosol was emitted from the tropical forest fire per unit of fuel combustion (EFOM of 8.00 ± 2.53 g kg-1, EFOC of 5.00 ± 1.58 g kg-1) compared to the Cerrado fires (EFOM of 1.31 ± 0.42 g kg-1, EFOC of 0.82 ± 0.26 g kg-1). Particulate-phase species emitted from the fires sampled are generally lower than those reported in previous studies and in emission inventories, which is likely a combination of differences in fire combustion efficiency and fuel mixture, along with different measurement techniques. Previous modelling studies focussed on the biomass burning season in tropical South

Predictive emission monitoring system (PEMS) for emission control in biomass fired plants; Predikterande emissionsmaetsystem (PEMS) foer emissionskontroll i biobraensleeldade foerbraenningsanlaeggningar

Energy Technology Data Exchange (ETDEWEB)

Harnevie, H; Sarkoezi, L; Trenkle, S

1996-08-01

An alternative method for estimation of NO{sub x}-emissions from biomass fired plants has been investigated. The method, `Predictive emission monitoring` (PEMS), implicates the creation of a mathematical formula. The formula expresses the relations between NO{sub x}-emissions and various operating and external parameters, such as flue gas temperature, excess combustion air and heat load. In this study the applicability of PEMS has been tested for two plants both of type travelling stokers. The most important results of the study are: PEMS is suitable for emission monitoring for some types of biomass fired plants (for example travelling stokers) even if the plant is fired with fuel with varying water content. In most cases it should be sufficient if the relation is based on oxygen level in the flue gas and plant load, with the possible addition of flue gas temperature and/or furnace temperature rate. These parameters are usually measured in any case, which means that no additional investment in instrumentation is necessary. In this study many measured parameters (for example the throttle levels) did not affect the NO{sub x}-emissions. A PEMS relation is only applicable for a specific plant and for a fixed validity range. Thus the function should be performed in such a way that it covers the limits of the operating parameters of the plant. Usage of different fuels or drift optimization can only be done within the validity range. Good combustion conditions could be necessary to receive a usable PEMS-function. Before creating the PEMS-function the combustion and the emission levels must be optimized. In plants with very fluctuating combustion, for example fixed stokers, it is possible that PEMS leads to not satisfying results. The total cost for a PEM-function can be calculated to be about 50-70% compared to a CEM during a period of a decade. 8 refs, 13 figs, 15 tabs, 8 appendices

Review about corrosion of superheaters tubes in biomass plants

International Nuclear Information System (INIS)

Berlanga-Labari, C.; Fernandez-Carrasquilla, J.

2006-01-01

The design of new biomass-fired power plants with increased steam temperature raises concerns of high-temperature corrosion. The high potassium and chlorine contents in many biomass, specially in wheat straw, are potentially harmful elements with regard to corrosion. Chlorine may cause accelerated corrosion resulting in increased oxidation, metal wastage, internal attack, void formations and loose non-adherent scales. The most severe corrosion problems in biomass-fired systems are expected to occur due to Cl-rich deposits formed on superheater tubes. In the first part of this revision the corrosion mechanism proposed are described in function of the conditions and compounds involved. The second part is focused on the behaviour of the materials tested so far in the boiler and in the laboratory. First the traditional commercial alloys are studied and secondly the new alloys and the coasting. (Author). 102 refs

OH-initiated Aging of Biomass Burning Aerosol during FIREX

Science.gov (United States)

Lim, C. Y.; Hagan, D. H.; Cappa, C. D.; Kroll, J. H.; Coggon, M.; Koss, A.; Sekimoto, K.; De Gouw, J. A.; Warneke, C.

2017-12-01

Biomass burning emissions represent a major source of fine particulate matter to the atmosphere, and this source will likely become increasingly important in the future due to changes in the Earth's climate. Understanding the effects that increased fire emissions have on both air quality and climate requires understanding the composition of the particles emitted, since chemical and physical composition directly impact important particle properties such as absorptivity, toxicity, and cloud condensation nuclei activity. However, the composition of biomass burning particles in the atmosphere is dynamic, as the particles are subject to the condensation of low-volatility vapors and reaction with oxidants such as the hydroxyl radical (OH) during transport. Here we present a series of laboratory chamber experiments on the OH-initiated aging of biomass burning aerosol performed at the Fire Sciences Laboratory in Missoula, MT as part of the Fire Influences on Regional and Global Environments Experiment (FIREX) campaign. We describe the evolution of biomass burning aerosol produced from a variety of fuels operating the chamber in both particle-only and gas + particle mode, focusing on changes to the organic composition. In particle-only mode, gas-phase biomass burning emissions are removed before oxidation to focus on heterogeneous oxidation, while gas + particle mode includes both heterogeneous oxidation and condensation of oxidized volatile organic compounds onto the particles (secondary organic aerosol formation). Variability in fuels and burning conditions lead to differences in aerosol loading and secondary aerosol production, but in all cases aging results in a significant and rapid increases in the carbon oxidation state of the particles.

Port Graham Community Building Biomass Heating Design Project

Energy Technology Data Exchange (ETDEWEB)

Norman, Patrick [Port Graham Village Corporation, Anchorage, AK (United States); Sink, Charles [Chugachmiut, Anchorage, Alaska (United States)

2015-04-30

Native Village of Port Graham completed preconstruction activities to prepare for construction and operations of a cord wood biomass heating system to five or more community buildings in Port Graham, Alaska. Project Description Native Village of Port Graham (NVPG) completed preconstruction activities that pave the way towards reduced local energy costs through the construction and operations of a cord wood biomass heating system. NVPG plans include installation of a GARN WHS 3200 Boiler that uses cord wood as fuel source. Implementation of the 700,000 Btu per hour output biomass community building heat utility would heat 5-community buildings in Port Graham, Alaska. Heating system is estimated to displace 85% of the heating fuel oil or 5365 gallons of fuel on an annual basis with an estimated peak output of 600,000 Btu per hour. Estimated savings is $15,112.00 per year. The construction cost estimate made to install the new biomass boiler system is estimated $251,693.47 with an additional Boiler Building expansion cost estimated at $97,828.40. Total installed cost is estimated $349,521.87. The WHS 3200 Boiler would be placed inside a new structure at the old community Water Plant Building site that is controlled by NVPG. Design of the new biomass heat plant and hot water loop system was completed by Richmond Engineering, NVPG contractor for the project. A hot water heat loop system running off the boiler is designed to be placed underground on lands controlled by NVPG and stubbed to feed hot water to existing base board heating system in the following community buildings: 1. Anesia Anahonak Moonin Health and Dental Clinic 2. Native Village of Port Graham offices 3. Port Graham Public Safety Building/Fire Department 4. Port Graham Corporation Office Building which also houses the Port Graham Museum and Head Start Center 5. North Pacific Rim Housing Authority Workshop/Old Fire Hall Existing community buildings fuel oil heating systems are to be retro-fitted to

Impact of deforestation on biomass burning in the tropics

International Nuclear Information System (INIS)

Hao, W.M.; Liu, M.H.; Ward, D.E.

1994-01-01

Fires are widely used for various land use practices in tropical countries. Large amounts of trace gases and aerosol particles are produced during the fires. It is important to assess the potential impact of these gases and particulate matter on the chemistry of the atmosphere and global climate. One of the largest uncertainties in quantifying the effects is the lack of information on the source strengths. The authors quantify the amount of biomass burned due to deforestation in each tropical country on basis of the deforestation rate, the above ground density, and the fraction of above ground biomass burned. Approximately 725 Tg of biomass were burned in 1980 and 984 Tg were burned in 1990. The 36% increase took place mostly in Latin America and tropical Asia. The largest source was Brazil, contributing about 29% of the total biomass burned in the tropics. The second largest source was Indonesia accounting for 10%, followed by Zaire accounting for about 8%. The burning of biomass due to increased deforestation has resulted in an additional 33 Tg CO and 2.5 Tg CH 4 emitted annually to the atmosphere from 1980 to 1990

Biomass Combustion Control and Stabilization Using Low-Cost Sensors

Directory of Open Access Journals (Sweden)

Ján Piteľ

2013-01-01

Full Text Available The paper describes methods for biomass combustion process control and burning stabilization based on low-cost sensing of carbon monoxide emissions and oxygen concentration in the flue gas. The designed control system was tested on medium-scale biomass-fired boilers and some results are evaluated and presented in the paper.

Low crosstalk Arrayed Waveguide Grating with Cascaded Waveguide Grating Filter

International Nuclear Information System (INIS)

Deng Yang; Liu Yuan; Gao Dingshan

2011-01-01

We propose a highly compact and low crosstalk arrayed waveguide grating (AWG) with cascaded waveguide grating (CWGF). The side lobes of the silicon nanowire AWG, which are normally introduced by fabrication errors, can be effectively suppressed by the CWGF. And the crosstalk can be improved about 15dB.

Forestry-based biomass economic and financial information and tools: An annotated bibliography

Science.gov (United States)

Dan Loeffler; Jason Brandt; Todd Morgan; Greg Jones

2010-01-01

This annotated bibliography is a synthesis of information products available to land managers in the western United States regarding economic and financial aspects of forestry-based woody biomass removal, a component of fire hazard and/or fuel reduction treatments. This publication contains over 200 forestry-based biomass papers, financial models, sources of biomass...

An ultra-high-vacuum multiple grating chamber and scan drive with improved grating change

International Nuclear Information System (INIS)

Hulbert, S.L.; Holly, D.J.; Middleton, F.H.; Wallace, D.J.; Wisconsin Univ., Stoughton, WI; Wisconsin Univ., Stoughton, WI

1989-01-01

We describe a new grating chamber and scan drive which has been designed, built, and tested by Physical Sciences Laboratory of the University of Wisconsin for the new high flux, high-resolution spectroscopy branch line of the TOK hybrid wiggler/undulator on the NSLS VUV ring. The chamber will contain spherical gratings to be used in the Spherical Grating Monochromator (SGM) configuration introduced by Chen and Sette. The grating chamber houses five 180 mm x 35 mm x 30 mm gratings capable of scanning a range of 12 degree (-14 degree to +8 degree with respect to the incoming beam direction) for VUV and soft X-ray diffraction. The gratings can be switched and precisely indexed while under ultra-high vacuum (UHV) at any scan angle and are mechanically isolated from the vacuum chamber to prevent inaccuracies due to chamber distortions. The gratings can separately be adjusted for height, yaw, pitch, and roll, with the latter three performed while in vacuo. The scan drive provides a resolution of 0.03 arc sec with linearity over the 12 degree range of ∼1.5 arc sec and absolute reproducibility of 1 arc sec. 5 refs., 5 figs

ASEAN grid-connected biomass residues fired cogeneration plants

International Nuclear Information System (INIS)

Adnan, M.F.; Alias, R.

2006-01-01

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

Rheology of fly ashes from coal and biomass co-combustion

DEFF Research Database (Denmark)

Arvelakis, Stelios; Frandsen, Flemming

2010-01-01

The presence of large amounts of alkali metals, chlorine and sulphur in most biomass fuels - compared to coal - can create serious ash-related problems such as deposition, agglomeration and/or corrosion. This paper discusses the viscosity characteristics of fly ash from the co-combustion of various...... coal/biomass blends in a pilot scale pf-boiler. The produced data provide information on the melting of the ash and its flow characteristics, as a function of temperature, which may be used to modify the temperature profile of the boiler in order to avoid slagging. Straw co-firing lowers the ash...... viscosity leading to higher stickiness of the ash particles. Wood co-firing has only minor effects, due to the composition of wood ash and the low percentage of wood in the coal/biomass blend....

Biomass ash utilization

Energy Technology Data Exchange (ETDEWEB)

Bristol, D.R.; Noel, D.J.; O`Brien, B. [HYDRA-CO Operations, Inc., Syracuse, NY (United States); Parker, B. [US Energy Corp., Fort Fairfield, ME (United States)

1993-12-31

This paper demonstrates that with careful analysis of ash from multiple biomass and waste wood fired power plants that most of the ash can serve a useful purpose. Some applications require higher levels of consistency than others. Examples of ash spreading for agricultural purposes as a lime supplement for soil enhancement in Maine and North Carolina, as well as a roadbase material in Maine are discussed. Use of ash as a horticultural additive is explored, as well as in composting as a filtering media and as cover material for landfills. The ash utilization is evaluated in a framework of environmental responsibility, regulations, handling and cost. Depending on the chemical and physical properties of the biomass derived fly ash and bottom ash, it can be used in one or more applications. Developing a program that utilizes ash produced in biomass facilities is environmentally and socially sound and can be financially attractive.

Global burned area and biomass burning emissions from small fires

NARCIS (Netherlands)

Randerson, J.T; Chen, Y.; van der Werf, 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

[Ground-clearing fires in the amazon and respiratory disease].

Science.gov (United States)

Gonçalves, Karen dos Santos; de Castro, Hermano Albuquerque; Hacon, Sandra de Souza

2012-06-01

The intentional burning of forest biomass commonly known as "ground-clearing fires" is an age-old and widespread practice in the country and is seen as a major contributor to global emissions of greenhouse gases. However, global awareness of their potential impact is relatively recent. The occurrence of large ground-clearing fires in the Brazilian and international scenarios drew attention to the problem, but the measures taken to prevent and/or control the fires are still insufficient. In the Amazon region, with distinct geographical and environmental features from the rest of the country, with its historic process of land occupation, every year the ground-clearing fires expose larger portions of the population making them vulnerable to its effects. In this context, this non-systematic review presents the papers written over the past five years about the fires in the Brazilian Amazon and respiratory illness. The main objective is to provide information for managers and leaders on environmental issues about the problems related to biomass burning in the Amazon region.

Off-plane x-ray reflection grating fabrication

Science.gov (United States)

Peterson, Thomas J.; DeRoo, Casey T.; Marlowe, Hannah; McEntaffer, Randall L.; Miles, Drew M.; Tutt, James H.; Schultz, Ted B.

2015-09-01

Off-plane X-ray diffraction gratings with precision groove profiles at the submicron scale will be used in next generation X-ray spectrometers. Such gratings will be used on a current NASA suborbital rocket mission, the Off-plane Grating Rocket Experiment (OGRE), and have application for future grating missions. The fabrication of these gratings does not come without challenges. High performance off-plane gratings must be fabricated with precise radial grating patterns, optically at surfaces, and specific facet angles. Such gratings can be made using a series of common micro-fabrication techniques. The resulting process is highly customizable, making it useful for a variety of different mission architectures. In this paper, we detail the fabrication method used to produce high performance off-plane gratings and report the results of a preliminary qualification test of a grating fabricated in this manner. The grating was tested in the off-plane `Littrow' configuration, for which the grating is most efficient for a given diffraction order, and found to achieve 42% relative efficiency in the blaze order with respect to all diffracted light.

Biomass electric technologies: Status and future development

International Nuclear Information System (INIS)

Bain, R.L.; Overend, R.P.

1992-01-01

At the present time, there axe approximately 6 gigawatts (GWe) of biomass-based, grid-connected electrical generation capacity in the United States. This capacity is primarily combustion-driven, steam-turbine technology, with the great majority of the plants of a 5-50 megawatt (MW) size and characterized by heat rates of 14,770-17,935 gigajoules per kilowatt-hour (GJ/kWh) (14,000-17,000 Btu/kWh or 18%-24% efficiency), and with installed capital costs of $1,300-$1,500/kW. Cost of electricity for existing plants is in the $0.065-$O.08/kWh range. Feedstocks are mainly waste materials; wood-fired systems account for 88% of the total biomass capacity, followed by agricultural waste (3%), landfill gas (8%), and anaerobic digesters (1%). A significant amount of remote, non-grid-connected, wood-fired capacity also exists in the paper and wood products industry. This chapter discusses biomass power technology status and presents the strategy for the U.S. Department of Energy (DOE) Biomass Power Program for advancing biomass electric technologies to 18 GWe by the year 2010, and to greater than 100 GWe by the year 2030. Future generation systems will be characterized by process efficiencies in the 35%-40% range, by installed capital costs of $770-$900/kW, by a cost of electricity in the $0.04-$O.05/kWh range, and by the use of dedicated fuel-supply systems. Technology options such as integrated gasification/gas-turbine systems, integrated pyrolysis/gas-turbine systems, and innovative direct-combustion systems are discussed, including present status and potential growth. This chapter also presents discussions of the U.S. utility sector and the role of biomass-based systems within the industry, the potential advantages of biomass in comparison to coal, and the potential environmental impact of biomass-based electricity generation

Holocene fire dynamics in Fennoscandia

Science.gov (United States)

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

2015-04-01

Prescribed burning is advocated in Fennoscandia to promote regeneration and to encourage biodiversity. This method of forest management is based on the perception that fire was much more frequent in the recent past and over a century of active fire suppression has created a boreal forest ecosystem almost free of natural fire. The absence of fire is thought to have contributed to the widespread dominance of Picea abies (Norway spruce) with the successive spruce dominated forest further reducing fire ignition potential. However, humans have altered the natural fire dynamics of Fennoscandia since the early- to mid-Holocene and disentangling the anthropogenic driven fire dynamics from the natural fire dynamics is challenging. Through palaeoecology and sedimentary charcoal deposits we are able to explore the Holocene spatial and temporal variability and changing drivers of fire and vegetation dynamics in Fennoscandia. At the local-scale, two forest hollow environments (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 ecosystem disturbance may have aided this spread. The expansion of spruce led to a step-wise reduction in regional biomass

Holocene fire, vegetation, and climate dynamics inferred from charcoal and pollen record in the eastern Tibetan Plateau

Science.gov (United States)

Zhao, Wenwei; Zhao, Yan; Qin, Feng

2017-10-01

Understanding fire history and its driving mechanisms can provide valuable insights into present fire regime (intensity, severity and frequency), the interplay between vegetation and fire, and trigger of fire activities. Here we reconstruct the Holocene fire history in the Zoige Basin on the eastern Tibetan Plateau, on the basis of sedimentary micro-charcoal record over the last 10.0 ka (1 ka = 1000 cal yr BP) and discuss the influences of vegetation and climate on fire dynamics. Our results show that regional fire was active at 10.0-3.3 ka and a significant decrease in fire activity characterized the period after 3.3 ka. The high regional fire frequency at 10.0-3.3 ka is consistent with the forested landscape suggested by high affinity scores of cool mixed forest biome (mainly consisted of spruce), implying that fire dynamics during this period was generally controlled by the variations of arboreal biomass and summer temperature. During 6.3-4.6 ka the prevailing Asian summer monsoon provided increased moisture to this region and thus suppressed fire activities to an extent, despite the availability of abundant biomass. Declined tree biomass after 3.3 ka probably accounted for the decreased fire activities. In addition, two successive fire events at ca. 3.5-3.3 ka were likely responsible for the subsequent abrupt decline of forest components in the landscape.

The biomass burning contribution to climate–carbon-cycle feedback

Directory of Open Access Journals (Sweden)

S. P. Harrison

2018-05-01

Full Text Available Temperature exerts strong controls on the incidence and severity of fire. All else equal, warming is expected to increase fire-related carbon emissions, and thereby atmospheric CO2. But the magnitude of this feedback is very poorly known. We use a single-box model of the land biosphere to quantify this positive feedback from satellite-based estimates of biomass burning emissions for 2000–2014 CE and from sedimentary charcoal records for the millennium before the industrial period. We derive an estimate of the centennial-scale feedback strength of 6.5 ± 3.4 ppm CO2 per degree of land temperature increase, based on the satellite data. However, this estimate is poorly constrained, and is largely driven by the well-documented dependence of tropical deforestation and peat fires (primarily anthropogenic on climate variability patterns linked to the El Niño–Southern Oscillation. Palaeo-data from pre-industrial times provide the opportunity to assess the fire-related climate–carbon-cycle feedback over a longer period, with less pervasive human impacts. Past biomass burning can be quantified based on variations in either the concentration and isotopic composition of methane in ice cores (with assumptions about the isotopic signatures of different methane sources or the abundances of charcoal preserved in sediments, which reflect landscape-scale changes in burnt biomass. These two data sources are shown here to be coherent with one another. The more numerous data from sedimentary charcoal, expressed as normalized anomalies (fractional deviations from the long-term mean, are then used – together with an estimate of mean biomass burning derived from methane isotope data – to infer a feedback strength of 5.6 ± 3.2 ppm CO2 per degree of land temperature and (for a climate sensitivity of 2.8 K a gain of 0.09 ± 0.05. This finding indicates that the positive carbon cycle feedback from increased fire provides a substantial

Developing Biomass Equations for Western Hemlock and Red Alder Trees in Western Oregon Forests

Science.gov (United States)

Krishna Poudel; Hailemariam Temesgen

2016-01-01

Biomass estimates are required for reporting carbon, assessing feedstock availability, and assessing forest fire threat. We developed diameter- and height-based biomass equations for Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and red alder (Alnus rubra Bong.) trees in Western Oregon. A system of component biomass...

A Greenhouse Gas Balance of Electricity Production from Co-firing Palm Oil Products from Malaysia

International Nuclear Information System (INIS)

Wicke, B.; Dornburg, V.; Faaij, A.; Junginger, M.

2007-05-01

The Netherlands imports significant quantities of biomass for energy production, among which palm oil has been used increasingly for co-firing in existing gas-fired power plants for renewable electricity production. Imported biomass, however, can not simply be considered a sustainable energy source. The production and removal of biomass in other places in the world result in ecological, land-use and socio-economic impacts and in GHG emissions (e.g. for transportation). As a result of the sustainability discussions, the Cramer Commission in the Netherlands has formulated (draft) criteria and indicators for sustainable biomass production. This study develops a detailed methodology for determining the GHG balance of co-firing palm oil products in the Netherlands based on the Cramer Commission methodology. The methodology is applied to a specific bio-electricity chain: the production of palm oil and a palm oil derivative, palm fatty acid distillate (PFAD), in Northeast Borneo in Malaysia, their transport to the Netherlands and co-firing with natural gas for electricity production at the Essent Claus power plant

Release of Corrosive Species above the Grate in a Waste Boiler and the Implication for Improved Electrical Efficiency

DEFF Research Database (Denmark)

Bøjer, Martin; Jensen, Peter Arendt; Dam-Johansen, Kim

2010-01-01

A relatively low electrical efficiency of 20−25% is obtained in typical west European waste boilers. Ash species released from the grate combustion zone form boiler deposits with high concentrations of Cl, Na, K, Zn, Pb, and S that cause corrosion of superheater tubes at high temperature....... The superheater steam temperature has to be limited to around 425 °C, and thereby, the electrical efficiency remains low compared to wood or coal-fired boilers. If a separate part of the flue gas from the grate has a low content of corrosive species, it may be used to superheat steam to a higher temperature......, and thereby, the electrical efficiency of the plant can be increased. In this study, the local temperature, the gas concentrations of CO, CO2, and O2, and the release of the volatile elements Cl, S, Na, K, Pb, Zn, Cu, and Sn were measured above the grate in a waste boiler to investigate if a selected fraction...

Laboratory Studies of Carbon Emission from Biomass Burning for use in Remote Sensing

Science.gov (United States)

Wald, Andrew E.; Kaufman, Yoram J.

1998-01-01

Biomass burning is a significant source of many trace gases in the atmosphere. Up to 25% of the total anthropogenic carbon dioxide added to the atmosphere annually is from biomass burning. However, this gaseous emission from fires is not directly detectable from satellite. Infrared radiance from the fires is. In order to see if infrared radiance can be used as a tracer for these emitted gases, we made laboratory measurements to determine the correlation of emitted carbon dioxide, carbon monoxide and total burned biomass with emitted infrared radiance. If the measured correlations among these quantities hold in the field, then satellite-observed infrared radiance can be used to estimate gaseous emission and total burned biomass on a global, daily basis. To this end, several types of biomass fuels were burned under controlled conditions in a large-scale combustion laboratory. Simultaneous measurements of emitted spectral infrared radiance, emitted carbon dioxide, carbon monoxide, and total mass loss were made. In addition measurements of fuel moisture content and fuel elemental abundance were made. We found that for a given fire, the quantity of carbon burned can be estimated from 11 (micro)m radiance measurements only within a factor of five. This variation arises from three sources, 1) errors in our measurements, 2) the subpixel nature of the fires, and 3) inherent differences in combustion of different fuel types. Despite this large range, these measurements can still be used for large-scale satellite estimates of biomass burned. This is because of the very large possible spread of fire sizes that will be subpixel as seen by Moderate Resolution Imaging Spectroradiometer (MODIS). Due to this large spread, even relatively low-precision correlations can still be useful for large-scale estimates of emitted carbon. Furthermore, such estimates using the MODIS 3.9 (micro)m channel should be even more accurate than our estimates based on 11 (micro)m radiance.

Deep-etched sinusoidal polarizing beam splitter grating.

Science.gov (United States)

Feng, Jijun; Zhou, Changhe; Cao, Hongchao; Lv, Peng

2010-04-01

A sinusoidal-shaped fused-silica grating as a highly efficient polarizing beam splitter (PBS) is investigated based on the simplified modal method. The grating structure depends mainly on the ratio of groove depth to grating period and the ratio of incident wavelength to grating period. These ratios can be used as a guideline for the grating design at different wavelengths. A sinusoidal-groove PBS grating is designed at a wavelength of 1310 nm under Littrow mounting, and the transmitted TM and TE polarized waves are mainly diffracted into the zeroth order and the -1st order, respectively. The grating profile is optimized by using rigorous coupled-wave analysis. The designed PBS grating is highly efficient (>95.98%) over the O-band wavelength range (1260-1360 nm) for both TE and TM polarizations. The sinusoidal grating can exhibit higher diffraction efficiency, larger extinction ratio, and less reflection loss than the rectangular-groove PBS grating. By applying wet etching technology on the rectangular grating, which was manufactured by holographic recording and inductively coupled plasma etching technology, the sinusoidal grating can be approximately fabricated. Experimental results are in agreement with theoretical values.

Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

DEFF Research Database (Denmark)

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

2002-01-01

This paper presents an analysis of the possibilities for improving the efficiency of an indirectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas, or pyrolysis gas. {The interest in this cycle arise from a recent...... demonstration of a two-stage gasification process through construction of several plants.} A preliminary analysis of the ideal recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained...

Near-field emission profiling of tropical forest and Cerrado fires in Brazil during SAMBBA 2012

Directory of Open Access Journals (Sweden)

A. K. Hodgson

2018-04-01

Full Text Available We profile trace gas and particulate emissions from near-field airborne measurements of discrete smoke plumes in Brazil during the 2012 biomass burning season. The South American Biomass Burning Analysis (SAMBBA Project conducted during September and October 2012 sampled across two distinct fire regimes prevalent in the Amazon Basin. Combined measurements from a Compact Time-of-Flight Aerosol Mass Spectrometer (C-ToF-AMS and a Single Particle Soot Photometer (SP2 are reported for the first time in a tropical biomass burning environment. Emissions from a mostly smouldering tropical forest wildfire in Rondônia state and numerous smaller flaming Cerrado fires in Tocantins state are presented. While the Cerrado fires appear to be representative of typical fire conditions in the existing literature, the tropical forest wildfire likely represents a more extreme example of biomass burning with a bias towards mostly smouldering emissions. We determined fire-integrated modified combustion efficiencies, emission ratios and emission factors for trace gas and particulate components for these two fire types, alongside aerosol microphysical properties. Seven times more black carbon was emitted from the Cerrado fires per unit of fuel combustion (EFBC of 0.13 ± 0.04 g kg−1 compared to the tropical forest fire (EFBC of 0.019 ± 0.006 g kg−1, and more than 6 times the amount of organic aerosol was emitted from the tropical forest fire per unit of fuel combustion (EFOM of 8.00 ± 2.53 g kg−1, EFOC of 5.00 ± 1.58 g kg−1 compared to the Cerrado fires (EFOM of 1.31 ± 0.42 g kg−1, EFOC of 0.82 ± 0.26 g kg−1. Particulate-phase species emitted from the fires sampled are generally lower than those reported in previous studies and in emission inventories, which is likely a combination of differences in fire combustion efficiency and fuel mixture, along with different measurement techniques. Previous

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

Science.gov (United States)

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

2014-11-01

Industrial CO2-rich flue-gases, owing to their eco-toxicity, have yet to be practically exploited for microalgal biomass and lipid production. In this study, various autotrophic and mixotrophic culture modes for an oleaginous microalga, Chlorella sp. KR-1 were compared for the use in actual coal-fired flue-gas. Among the mixotrophic conditions tested, the fed-batch feedings of glucose and the supply of air in dark cycles showed the highest biomass (561 mg/L d) and fatty-acid methyl-ester (168 mg/L d) productivities. This growth condition also resulted in the maximal population of microalgae and the minimal population and types of KR-1-associated-bacterial species as confirmed by particle-volume-distribution and denaturing-gradient-gel-electrophoresis (DGGE) analyses. Furthermore, microalgal lipid produced was assessed, based on its fatty acid profile, to meet key biodiesel standards such as saponification, iodine, and cetane numbers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Theoretical Investigation of Subwavelength Gratings and Vertical Cavity Lasers Employing Grating Structures

DEFF Research Database (Denmark)

Taghizadeh, Alireza

This thesis deals with theoretical investigations of a newly proposed grating structure, referred to as hybrid grating (HG) as well as vertical cavity lasers based on the grating reflectors. The HG consists of a near-subwavelength grating layer and an unpatterned high-refractive-index cap layer...... directions, which is analogous to electronic quantum wells in conduction or valence bands. Several interesting configurations of heterostructures have been investigated and their potential in fundamental physics study and applications are discussed. For numerical and theoretical studies, a three...... feasibility than the HCG-based ones. Furthermore, the concept of cavity dispersion in vertical cavities is introduced and its importance in the modal properties is numerically investigated. The dispersion curvature of a cavity mode is interpreted as the effective photon mass of the cavity mode. In a vertical...

DEVELOPMENT AND TESTING OF COMPOUND FUEL CHAMBER WITHOUT A GRATE FOR HOUSEHOLD FURNACE

Directory of Open Access Journals (Sweden)

Shevyakov Vladimir Viktorovich

2018-02-01

Full Text Available In hearth furnaces, the firewood is burned more cleanly with less carbon monoxide at the outlet. The disadvantage of such fireboxes is a longer process of coal burnout than in grate-fired furnaces. In furnaces with a grate, the burnout time of coals is less, which makes it possible to finish the combustion process more quickly and close the outlet latch. This increases the efficiency of the furnace but to further reduce the time of burning out the coals they have to be raked and burned on the grate. This complicates the process of operating the furnace itself. The proposed design of the compound firebox allows us to improve characteristics of both the firebox itself and the entire furnace. Research objectives: creation and study of a compound firebox that increases the efficiency of the furnace and simplifies the furnace maintenance process with the values of carbon monoxide at the outlet comparable to hearth furnaces. Materials and methods: a detailed analysis of hearth fuel chambers ECO+ was carried out according to the amount of carbon monoxide at the outlet. The results of the analysis are used for comparison with compound fuel chamber. The structure of the compound firebox was chosen based on the results of preliminary tests of several fuel chambers proposed and tested by the author in the furnace PDKSh-2.0. A peculiarity of the structure of the compound firebox is the absence of a grate and the presence of a narrow slit in the lower part of the firebox through which the incoming air enters the firewood. Between the walls of the firebox and firewood, skids are installed, forming an air gap, through which the inlet air is uniformly supplied to the entire firewood supply. With gradual combustion of firewood and formation of coal, the firewood descends to the bottom of the firebox, where they intensively burn out in the maximum air flow. Compound firebox consists of several parts, it is made of steel with a thickness of 4.0 mm and installed

COFIRING OF BIOMASS AT THE UNIVERSITY OF NORTH DAKOTA

Energy Technology Data Exchange (ETDEWEB)

Phillip N. Hutton

2002-01-01

A project funded by the U.S. Department of Energy's National Energy Technology Laboratory was completed by the Energy & Environmental Research Center to explore the potential for cofiring biomass at the University of North Dakota (UND). The results demonstrate how 25% sunflower hulls can be cofired with subbituminous coal and provide a 20% return on investment or 5-year payback for the modifications required to enable firing biomass. Significant outcomes of the study are as follows. A complete resource assessment presented all biomass options to UND within a 100-mile radius. Among the most promising options in order of preference were sunflower hulls, wood residues, and turkey manure. The firing of up to 28% sunflower hulls by weight was completed at the university's steam plant to identify plant modifications that would be necessary to enable cofiring sunflower hulls. The results indicated investments in a new equipment could be less than $408,711. Data collected from test burns, which were not optimized for biomass firing, resulted in a 15% reduction in sulfur and NO{sub x} emissions, no increase in opacity, and slightly better boiler efficiency. Fouling and clinkering potential were not evaluated; however, no noticeable detrimental effects occurred during testing. As a result of this study, UND has the potential to achieve a cost savings of approximately $100,000 per year from a $1,500,000 annual fossil fuel budget by implementing the cofiring of 25% sunflower hulls.

The impact of infield biomass burning on PM levels and its chemical composition.

Science.gov (United States)

Dambruoso, P; de Gennaro, G; Di Gilio, A; Palmisani, J; Tutino, M

2014-12-01

In the South of Italy, it is common for farmers to burn pruning waste from olive trees in spring. In order to evaluate the impact of the biomass burning source on the physical and chemical characteristics of the particulate matter (PM) emitted by these fires, a PM monitoring campaign was carried out in an olive grove. Daily PM10 samples were collected for 1 week, when there were no open fires, and when biomass was being burned, and at two different distances from the fires. Moreover, an optical particle counter and a polycyclic aromatic hydrocarbon (PAH) analyzer were used to measure the high time-resolved dimensional distribution of particles emitted and total PAHs concentrations, respectively. Chemical analysis of PM10 samples identified organic and inorganic components such as PAHs, ions, elements, and carbonaceous fractions (OC, EC). Analysis of the collected data showed the usefulness of organic and inorganic tracer species and of PAH diagnostic ratios for interpreting the impact of biomass fires on PM levels and on its chemical composition. Finally, high time-resolved monitoring of particle numbers and PAH concentrations was performed before, during, and after biomass burning, and these concentrations were seen to be very dependent on factors such as weather conditions, combustion efficiency, and temperature (smoldering versus flaming conditions), and moisture content of the wood burned.

Topo-edaphic controls over woody plant biomass in South African savannas

Directory of Open Access Journals (Sweden)

M. S. Colgan

2012-05-01

Full Text Available The distribution of woody biomass in savannas reflects spatial patterns fundamental to ecosystem processes, such as water flow, competition, and herbivory, and is a key contributor to savanna ecosystem services, such as fuelwood supply. While total precipitation sets an upper bound on savanna woody biomass, the extent to which substrate and terrain constrain trees and shrubs below this maximum remains poorly understood, often occluded by local-scale disturbances such as fire and trampling. Here we investigate the role of hillslope topography and soil properties in controlling woody plant aboveground biomass (AGB in Kruger National Park, South Africa. Large-area sampling with airborne Light Detection and Ranging (LiDAR provided a means to average across local-scale disturbances, revealing an unexpectedly linear relationship between AGB and hillslope-position on basalts, where biomass levels were lowest on crests, and linearly increased toward streams (R² = 0.91. The observed pattern was different on granite substrates, where AGB exhibited a strongly non-linear relationship with hillslope position: AGB was high on crests, decreased midslope, and then increased near stream channels (R² = 0.87. Overall, we observed 5-to-8-fold lower AGB on clayey, basalt-derived soil than on granites, and we suggest this is due to herbivore-fire interactions rather than lower hydraulic conductivity or clay shrinkage/swelling, as previously hypothesized. By mapping AGB within and outside fire and herbivore exclosures, we found that basalt-derived soils support tenfold higher AGB in the absence of fire and herbivory, suggesting high clay content alone is not a proximal limitation on AGB. Understanding how fire and herbivory contribute to AGB heterogeneity is critical to predicting future savanna carbon storage under a changing climate.

Curved VPH gratings for novel spectrographs

Science.gov (United States)

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.

Domestic biomass combustion and associated atmospheric emissions in West Africa

Science.gov (United States)

Brocard, Delphine; Lacaux, Jean-Pierre; Eva, Hugh

1998-03-01

Biofuel is the main source of energy for cooking and heating in Africa. In order to estimate the consumption of this resource at a regional level, a database with a spatial resolution of 1° latitude by 1° longitude of the distribution of the amounts of fuel wood and charcoal annually burned in West Africa has been derived. Chemical emission factors for fuel wood, for charcoal burning, and for charcoal fabrication measured during two field experiments are then used in conjunction with this database to produce a second 1° latitude by 1° longitude database of the emissions due to domestic fires for the region. A comparison of these emissions from domestic fires with those of savanna fires, the dominant form of biomass burning in tropical Africa, shows that the relative contribution of the wood fuel (i.e. fuel wood and charcoal) combustion is important for CH4 (46%), CO (42%), and nonmethane hydrocarbons (NMHC) (44%), less so for CO2 (32%). This source of biomass burning has a different spatial and temporal distribution than that of savanna fires and represents an atmospheric background noise throughout the year, whereas the savanna fires occur during a limited season.

The Influence of Rainfall, Vegetation, Elephants and People on Fire Frequency of Miombo Woodlands, Northern Mozambique

Science.gov (United States)

Ribeiro, N. S.; Okin, G. S.; Shugart, H. H.; Swap, R. J.

2008-12-01

Miombo woodlands are important in southern Africa as they occupy over 50% of the land and, their good and services support a large proportion of people in the region. Anthropogenic fires occur in miombo every year especially in the dry season (May - October). This study explores the influence of annual rainfall, elephant density, human density and corridors, and vegetation on the fire frequency. It was carried out in Niassa Reserve located in northern Mozambique, the largest and more pristine conservation area of miombo woodlands in the world. We used a time series analysis and statistical t-test of MODIS-derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) to explore the relationship between biomass and fire frequency. The influence of rainfall, elephants, people and vegetation on fire return was explored using a stepwise logistic regression analysis. The results of this study indicate that fire frequency is higher in places with high biomass at beginning of the dry season. In these areas fire seems to be more intense and to strongly reduce biomass in the late dry season. Land cover is the strongest predictor of fire frequency, but elephant density, annual rainfall and human corridors are also important.

Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study

Science.gov (United States)

Nolan W. Brewer; Alistair M.S. Smith; Jeffery A. Hatten; Philip E. Higuera; Andrew T. Hudak; Roger D. Ottmar; Wade T. Tinkham

2013-01-01

Biomass burning is a significant contributor to atmospheric carbon emissions but may also provide an avenue in which fire-affected ecosystems can accumulate carbon over time, through the generation of highly resistant fire-altered carbon. Identifying how fuel moisture, and subsequent changes in the fire behavior, relates to the production of fire-altered carbon is...

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

Science.gov (United States)

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

Characteristics of particulate-bound polycyclic aromatic hydrocarbons emitted from industrial grade biomass boilers.

Science.gov (United States)

Yang, Xiaoyang; Geng, Chunmei; Sun, Xuesong; Yang, Wen; Wang, Xinhua; Chen, Jianhua

2016-02-01

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic or mutagenic and are important toxic pollutants in the flue gas of boilers. Two industrial grade biomass boilers were selected to investigate the characteristics of particulate-bound PAHs: one biomass boiler retro-fitted from an oil boiler (BB1) and one specially designed (BB2) biomass boiler. One coal-fired boiler was also selected for comparison. By using a dilution tunnel system, particulate samples from boilers were collected and 10 PAH species were analyzed by gas chromatography-mass spectrometry (GC-MS). The total emission factors (EFs) of PAHs ranged from 0.0064 to 0.0380 mg/kg, with an average of 0.0225 mg/kg, for the biomass boiler emission samples. The total PAH EFs for the tested coal-fired boiler were 1.8 times lower than the average value of the biomass boilers. The PAH diagnostic ratios for wood pellets and straw pellets were similar. The ratio of indeno(1,2,3-cd)pyrene/[indeno(1,2,3-cd)pyrene+benzo(g,h,i)perylene] for the two biomass boilers was lower than those of the reference data for other burning devices, which can probably be used as an indicator to distinguish the emission of biomass boilers from that of industrial coal-fired boilers and residential stoves. The toxic potential of the emission from wood pellet burning was higher than that from straw pellet burning, however both of them were much lower than residential stove exhausts. Copyright © 2015. Published by Elsevier B.V.

Pyrolysis of biomass for hydrogen production

International Nuclear Information System (INIS)

Constantinescu, Marius; David, Elena; Bucura, Felicia; Sisu, Claudia; Niculescu, Violeta

2006-01-01

Biomass processing is a new technology within the area of renewable energies. Current energy supplies in the world are dominated by fossil fuels (some 80% of the total use of over 400 EJ per year). Nevertheless, about 10-15% of this demand is covered by biomass resources, making biomass by far the most important renewable energy source used to date. On average, in the industrialized countries biomass contributes some 9-13% to the total energy supplies, but in developing countries the proportion is as high as a fifth to one third. In quite a number of countries biomass covers even over 50 to 90% of the total energy demand. Classic application of biomass combustion is heat production for domestic applications. A key issue for bio-energy is that its use should be modernized to fit into a sustainable development path. Especially promising are the production of electricity via advanced conversion concepts (i.e. gasification and state-of-the-art combustion and co-firing) and modern biomass derived fuels like methanol, hydrogen and ethanol from ligno-cellulosic biomass, which can reach competitive cost levels within 1-2 decades (partly depending on price developments with petroleum). (authors)

Changes in forest biomass and linkage to climate and forest disturbances over Northeastern China.

Science.gov (United States)

Zhang, Yuzhen; Liang, Shunlin

2014-08-01

The forests of northeastern China store nearly half of the country's total biomass carbon stocks. In this study, we investigated the changes in forest biomass by using satellite observations and found that a significant increase in forest biomass took place between 2001 and 2010. To determine the possible reasons for this change, several statistical methods were used to analyze the correlations between forest biomass dynamics and forest disturbances (i.e. fires, insect damage, logging, and afforestation and reforestation), climatic factors, and forest development. Results showed that forest development was the most important contributor to the increasing trend of forest biomass from 2001 to 2010, and climate controls were the secondary important factor. Among the four types of forest disturbance considered in this study, forest recovery from fires, and afforestation and reforestation during the past few decades played an important role in short-term biomass dynamics. This study provided observational evidence and valuable information for the relationships between forest biomass and climate as well as forest disturbances. © 2014 John Wiley & Sons Ltd.

Burning of biomass waste

International Nuclear Information System (INIS)

Holm Christensen, B.; Evald, A.; Buelow, K.

1997-01-01

The amounts of waste wood from the Danish wood processing industry available for the energy market has been made. Furthermore a statement of residues based on biomass, including waste wood, used in 84 plants has been made. The 84 plants represent a large part of the group of purchasers of biomass. A list of biomass fuel types being used or being potential fuels in the future has been made. Conditions in design of plants of importance for the environmental impact and possibility of changing between different biomass fuels are illustrated through interview of the 84 plants. Emissions from firing with different types of residues based on biomass are illustrated by means of different investigations described in the literature of the composition of fuels, of measured emissions from small scale plants and full scale plants, and of mass balance investigations where all incoming and outgoing streams are analysed. An estimate of emissions from chosen fuels from the list of types of fuels is given. Of these fuels can be mentioned residues from particle board production with respectively 9% and 1% glue, wood pellets containing binding material with sulphur and residues from olive production. (LN)

Compatible above-ground biomass equations and carbon stock estimation for small diameter Turkish pine (Pinus brutia Ten.).

Science.gov (United States)

Sakici, Oytun Emre; Kucuk, Omer; Ashraf, Muhammad Irfan

2018-04-15

Small trees and saplings are important for forest management, carbon stock estimation, ecological modeling, and fire management planning. Turkish pine (Pinus brutia Ten.) is a common coniferous species and comprises 25.1% of total forest area of Turkey. Turkish pine is also important due to its flammable fuel characteristics. In this study, compatible above-ground biomass equations were developed to predict needle, branch, stem wood, and above-ground total biomass, and carbon stock assessment was also described for Turkish pine which is smaller than 8 cm diameter at breast height or shorter than breast height. Compatible biomass equations are useful for biomass prediction of small diameter individuals of Turkish pine. These equations will also be helpful in determining fire behavior characteristics and calculating their carbon stock. Overall, present study will be useful for developing ecological models, forest management plans, silvicultural plans, and fire management plans.

Spherical grating based x-ray Talbot interferometry

Energy Technology Data Exchange (ETDEWEB)

Cong, Wenxiang, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Xi, Yan, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Wang, Ge, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu [Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2015-11-15

Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

Spherical grating based x-ray Talbot interferometry

International Nuclear Information System (INIS)

Cong, Wenxiang; Xi, Yan; Wang, Ge

2015-01-01

Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

Oxy-fuel combustion of coal and biomass, the effect on radiative and convective heat transfer and burnout

Energy Technology Data Exchange (ETDEWEB)

Smart, John P.; Patel, Rajeshriben; Riley, Gerry S. [RWEnpower, Windmill Hill Business Park, Whitehill Way, Swindon, Wiltshire SN5 6PB, England (United Kingdom)

2010-12-15

This paper focuses on results of co-firing coal and biomass under oxy-fuel combustion conditions on the RWEn 0.5 MWt Combustion Test Facility (CTF). Results are presented of radiative and convective heat transfer and burnout measurements. Two coals were fired: a South African coal and a Russian Coal under air and oxy-fuel firing conditions. The two coals were also co-fired with Shea Meal at a co-firing mass fraction of 20%. Shea Meal was also co-fired at a mass fraction of 40% and sawdust at 20% with the Russian Coal. An IFRF Aerodynamically Air Staged Burner (AASB) was used. The thermal input was maintained at 0.5 MWt for all conditions studied. The test matrix comprised of varying the Recycle Ratio (RR) between 65% and 75% and furnace exit O{sub 2} was maintained at 3%. Carbon-in-ash samples for burnout determination were also taken. Results show that the highest peak radiative heat flux and highest flame luminosity corresponded to the lowest recycle ratio. The effect of co-firing of biomass resulted in lower radiative heat fluxes for corresponding recycle ratios. Furthermore, the highest levels of radiative heat flux corresponded to the lowest convective heat flux. Results are compared to air firing and the air equivalent radiative and convective heat fluxes are fuel type dependent. Reasons for these differences are discussed in the main text. Burnout improves with biomass co-firing under both air and oxy-fuel firing conditions and burnout is also seen to improve under oxy-fuel firing conditions compared to air. (author)

BIOMASS REBURNING - MODELING/ENGINEERING STUDIES

International Nuclear Information System (INIS)

Vladimir Zamansky; David Moyeda; Mark Sheldon

2000-01-01

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 tenth reporting period (January 1-March 31, 2000), EER and NETL R and D group continued to work on Tasks 2, 3, 4, and 5. Information regarding these tasks will be included in the next Quarterly Report. This report includes (Appendix 1) a conceptual design study for the introduction of biomass reburning in a working coal-fired utility boiler. This study was conducted under the coordinated SBIR program funded by the U. S. Department of Agriculture

The Flexibility of Pusher Furnace Grate

Directory of Open Access Journals (Sweden)

Słowik J.A.

2016-12-01

Full Text Available The lifetime of guide grates in pusher furnaces for heat treatment could be increased by raising the flexibility of their structure through, for example, the replacement of straight ribs, parallel to the direction of grate movement, with more flexible segments. The deformability of grates with flexible segments arranged in two orientations, i.e. crosswise (perpendicular to the direction of compression and lengthwise (parallel to the direction of compression, was examined. The compression process was simulated using SolidWorks Simulation program. Relevant regression equations were also derived describing the dependence of force inducing the grate deformation by 0.25 mm ‒ modulus of grate elasticity ‒ on the number of flexible segments in established orientations. These calculations were made in Statistica and Scilab programs. It has been demonstrated that, with the same number of segments, the crosswise orientation of flexible segments increases the grate structure flexibility in a more efficient way than the lengthwise orientation. It has also been proved that a crucial effect on the grate flexibility has only the quantity and orientation of segments (crosswise / lengthwise, while the exact position of segments changes the grate flexibility by less than 1%.

Wildland fire emissions, carbon and climate: Characterizing wildland fuels

Science.gov (United States)

David R. Weise; Clinton S. Wright

2013-01-01

Smoke from biomass fires makes up a substantial portion of global greenhouse gas, aerosol, and black carbon (GHG/A/BC) emissions. Understanding how fuel characteristics and conditions affect fire occurrence and extent, combustion dynamics, and fuel consumption is critical for making accurate, reliable estimates of emissions production at local, regional, national, and...

Solid biomass barometer

International Nuclear Information System (INIS)

Anon.

2011-01-01

The primary energy production from solid biomass in the European Union reached 79.3 Mtoe in 2010 which implies a growth rate of 8% between 2009 and 2010. The trend, which was driven deeper by Europe's particularly cold winter of 2009-2010, demonstrates that the economic down-turn failed to weaken the member states' efforts to structure the solid biomass sector. Heat consumption rose sharply: the volume of heat sold by heating networks increased by 18% and reached 6.7 Mtoe and if we consider the total heat consumption (it means with and without recovery via heating networks) the figure is 66 Mtoe in 2010, which amounts to 10.1% growth. The growth of electricity production continued through 2010 (8.3% up on 2009) and rose to 67 TWh but at a slower pace than in 2009 (when it rose by 11.3% on 2008). The situation of the main producer countries: Sweden, Finland, Germany and France is reviewed. It appears that cogeneration unit manufacturers and biomass power plant constructors are the main beneficiaries of the current biomass energy sector boom. There is a trend to replace coal-fired plants that are either obsolete or near their end of life with biomass or multi-fuel plants. These opportunities will enable the industry to develop and further exploit new technologies such as gasification, pyrolysis and torrefaction which will enable biomass to be turned into bio-coal. (A.C.)

Effects of fire on major forest ecosystem processes: an overview.

Science.gov (United States)

Chen, Zhong

2006-09-01

Fire and fire ecology are among the best-studied topics in contemporary ecosystem ecology. The large body of existing literature on fire and fire ecology indicates an urgent need to synthesize the information on the pattern of fire effects on ecosystem composition, structure, and functions for application in fire and ecosystem management. Understanding fire effects and underlying principles are critical to reduce the risk of uncharacteristic wildfires and for proper use of fire as an effective management tool toward management goals. This overview is a synthesis of current knowledge on major effects of fire on fire-prone ecosystems, particularly those in the boreal and temperate regions of the North America. Four closely related ecosystem processes in vegetation dynamics, nutrient cycling, soil and belowground process and water relations were discussed with emphases on fire as the driving force. Clearly, fire can shape ecosystem composition, structure and functions by selecting fire adapted species and removing other susceptible species, releasing nutrients from the biomass and improving nutrient cycling, affecting soil properties through changing soil microbial activities and water relations, and creating heterogeneous mosaics, which in turn, can further influence fire behavior and ecological processes. Fire as a destructive force can rapidly consume large amount of biomass and cause negative impacts such as post-fire soil erosion and water runoff, and air pollution; however, as a constructive force fire is also responsible for maintaining the health and perpetuity of certain fire-dependent ecosystems. Considering the unique ecological roles of fire in mediating and regulating ecosystems, fire should be incorporated as an integral component of ecosystems and management. However, the effects of fire on an ecosystem depend on the fire regime, vegetation type, climate, physical environments, and the scale of time and space of assessment. More ecosystem

The grating as an accelerating structure

International Nuclear Information System (INIS)

Fernow, R.C.

1991-02-01

This report considers the use of a diffraction grating as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of a grating. Calculations are made of the strength of the accelerating modes for structures with π and 2π phase advance per period and for incident waves polarized with either the E or H vector along the grooves of the grating. We consider examples of using gratings in a laser linac and in a grating lens. We also briefly examine previous results published about this subject. 36 refs

Enhanced Raman scattering in porous silicon grating.

Science.gov (United States)

Wang, Jiajia; Jia, Zhenhong; Lv, Changwu

2018-03-19

The enhancement of Raman signal on monocrystalline silicon gratings with varying groove depths and on porous silicon grating were studied for a highly sensitive surface enhanced Raman scattering (SERS) response. In the experiment conducted, porous silicon gratings were fabricated. Silver nanoparticles (Ag NPs) were then deposited on the porous silicon grating to enhance the Raman signal of the detective objects. Results show that the enhancement of Raman signal on silicon grating improved when groove depth increased. The enhanced performance of Raman signal on porous silicon grating was also further improved. The Rhodamine SERS response based on Ag NPs/ porous silicon grating substrates was enhanced relative to the SERS response on Ag NPs/ porous silicon substrates. Ag NPs / porous silicon grating SERS substrate system achieved a highly sensitive SERS response due to the coupling of various Raman enhancement factors.

Varied line-space gratings and applications

International Nuclear Information System (INIS)

McKinney, W.R.

1991-01-01

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

Tracking nitrogen oxides, nitrous acid, and nitric acid from biomass burning

Science.gov (United States)

Chai, J.; Miller, D. J.; Scheuer, E. M.; Dibb, J. E.; Hastings, M. G.

2017-12-01

Biomass burning emissions are an important source of atmospheric nitrogen oxides (NOx = NO + NO2) and nitrous acid (HONO), which play important roles in atmosphere oxidation capacity (hydroxyl radical and ozone formation) and have severe impacts on air quality and climate in the presence of sunlight and volatile organic compounds. However, tracking NOx and HONO and their chemistry in the atmosphere based on concentration alone is challenging. Isotopic analysis provides a potential tracking tool. In this study, we measured the nitrogen isotopic composition (δ15N) of NOx (NO + NO2) and HONO, and soluble HONO and HNO3 during the Fire Influence on Regional and Global Environments Experiment (FIREX) laboratory experiments at the Missoula Fire Laboratory. Our newly developed and validated annular denuder system (ADS) enabled us to effectively trap HONO prior to a NOx collection system in series for isotopic analysis. In total we investigated 25 "stack" fires of various biomass materials where the emissions were measured within a few seconds of production by the fire. HONO concentration was measured in parallel using mist chamber/ion chromatography (MC/IC). The recovered mean HONO concentrations from ADS during the burn of each fire agree well with that measured via MC/IC. δ15N-NOx ranged from -4.3 ‰ to + 7.0 ‰ with a median of 0.7 ‰. Combined with a similar, recent study by our group [Fibiger et al., ES&T, 2017] the δ15N-NOx follows a linear relationship with δ15N-biomass (δ15N-NOx =0.94 x δ15N-biomass +1.98; R2=0.72). δ15N-HONO ranged from -5.3 to +8.3 ‰ with a median of 1.4 ‰. While both HONO and NOx are sourced from N in the biomass fuel, the secondary formation of HONO likely induces fractionation of the N that leads to the difference between δ15N-NOx and δ15N-HONO. We found a correlation of δ15N-HONO= 0.86 x δ15N-NOx + 0.52 (R2=0.55), which can potentially be used to track the chemistry of HONO formation following fire emissions. The methods

A Five- Year CMAQ Model Performance for Wildfires and Prescribed Fires

Science.gov (United States)

Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. Two components of the biomass burning inventory, wildfires and prescribed fires are routinely estimated in the national emissio...

Talbot Carpet Simulation for X-ray grating interferometer

Energy Technology Data Exchange (ETDEWEB)

Kim, Youngju; Oh, Ohsung; Jeong, Hanseong; Kim, Jeongho; Lee, Seung Wook [Pusan National University, Busan (Korea, Republic of); Kim, Jongyul; Moon, Myungkook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

In this study, Talbot carpet simulator has been developed to visualize the X-ray grating interference patterns in grating interferometer. We have simulated X-ray interference for a variety of simulations and demonstrated a few examples in this summary. Grating interferometer produces interference of X-ray called Talbot pattern with gratings manufactured in micro scale. Talbot pattern is self-images of phase grating which develops interference as beam splitter that is one of gratings consisted of interferometer. As the other gratings, there are source grating makes coherence and analyze grating is used to analyze interference onto detector. Talbot carpet has been studied as the beam behavior which is distinguished with common X-ray imaging systems. It is helpful to understand grating interferometer and possible to expect beams' oscillation for designing theoretically. We confirm pattern has periodicity produced by interference after pi and pi/2 phase grating and changes in the perpendicular direction to entrance face according to phase objects.

Imaging properties of high aspect ratio absorption gratings for use in preclinical x-ray grating interferometry.

Science.gov (United States)

Trimborn, Barbara; Meyer, Pascal; Kunka, Danays; Zuber, Marcus; Albrecht, Frederic; Kreuer, Sascha; Volk, Thomas; Baumbach, Tilo; Koenig, Thomas

2016-01-21

X-ray grating interferometry is one among various methods that allow extracting the so-called phase and visibility contrasts in addition to the well-known transmission images. Crucial to achieving a high image quality are the absorption gratings employed. Here, we present an in-depth analysis of how the grating type and lamella heights influence the final images. Benchmarking gratings of two different designs, we show that a frequently used proxy for image quality, a grating's so-called visibility, is insufficient to predict contrast-to-noise ratios (CNRs). Presenting scans from an excised rat lung, we demonstrate that the CNRs obtained for transmission and visibility images anti-correlate. This is explained by the stronger attenuation implied by gratings that are engineered to provide high visibilities by means of an increased lamella height. We show that even the visibility contrast can suffer from this effect when the associated reduced photon flux on the detector is not outweighed by a corresponding gain in visibility. Resulting in an inevitable trade-off between the quality of the two contrasts, the question of how an optimal grating should be designed can hence only be answered in terms of Pareto optimality.

Intensified water storage loss by biomass burning in Kalimantan: Detection by GRACE

Science.gov (United States)

Han, Jiancheng; Tangdamrongsub, Natthachet; Hwang, Cheinway; Abidin, Hasanuddin Z.

2017-03-01

Biomass burning is the principal tool for land clearing and a primary driver of land use change in Kalimantan (the Indonesian part of Borneo island). Biomass burning here has consumed millions of hectares of peatland and swamp forests. It also degrades air quality in Southeast Asia, perturbs the global carbon cycle, threatens ecosystem health and biodiversity, and potentially affects the global water cycle. Here we present the optimal estimate of water storage changes over Kalimantan from NASA's Gravity Recovery and Climate Experiment (GRACE). Over August 2002 to December 2014, our result shows a north-south dipole pattern in the long-term changes in terrestrial water storage (TWS) and groundwater storage (GWS). Both TWS and GWS increase in the northern part of Kalimantan, while they decrease in the southern part where fire events are the most severe. The loss rates in TWS and GWS in the southern part are 0.56 ± 0.11 cm yr-1 and 0.55 ± 0.10 cm yr-1, respectively. We use GRACE estimates, burned area, carbon emissions, and hydroclimatic data to study the relationship between biomass burning and water storage losses. The analysis shows that extensive biomass burning results in excessive evapotranspiration, which then increases long-term water storage losses in the fire-prone region of Kalimantan. Our results show the potentials of GRACE and its follow-on missions in assisting water storage and fire managements in a region with extensive biomass burning such as Kalimantan.

Biomass partitioning and root morphology of savanna trees across a water gradient

NARCIS (Netherlands)

Tomlinson, K.W.; Sterck, F.J.; Bongers, F.; Silva, da D.A.; Barbosa, E.R.; Ward, D.; Bakker, F.T.; Kaauwen, van M.P.W.; Prins, H.H.T.; Bie, de S.; Langevelde, van F.

2012-01-01

1. Plant organ biomass partitioning has been hypothesized to be driven by resources, such that species from drier environments allocate more biomass to roots than species from wetter environments to access water at greater soil depths. In savanna systems, fire may select for greater allocation to

Geostationary satellite estimation of biomass burning in Amazonia during BASE-A

International Nuclear Information System (INIS)

Menzel, W.P.; Cutrim, E.C.; Prins, E.M.

1991-01-01

This chapter presents the results of using Geostationary Operational Environmental Satellite (GOES) Visible Infrared Spin Scan Radiometer Atmospheric Sounder (VAS) infrared window (3.9 and 11.2 microns) data to monitor biomass burning several times per day in Amazonia. The technique of Matson and Dozier using two window channels was adapted to GOES VAS infrared data to estimate the size and temperature of fires associated with deforestation in the vicinity of Alta Floresta, Brazil, during the Biomass Burning Airborne and Spaceborne Experiment - Amazonia (BASE-A). Although VAS data do not offer the spatial resolution available with AVHRR data 97 km versus 1 km, respectively, this decreased resolution does not seem to hinder the ability of the VAS instrument to detect fires; in some cases it proves to be advantageous in that saturation does not occur as often. VAS visible data are additionally helpful in verifying that the hot spots sensed in the infrared are actually related to fires. Furthermore, the fire plumes can be tracked in time to determine their motion and extent. In this way, the GOES satellite offers a unique ability to monitor diurnal variations in fire activity and transport of related aerosols

An emissions audit of a biomass combustor burning treated wood waste

International Nuclear Information System (INIS)

Jackson, P.M.; Jones, H.H.; King, P.G.

1993-01-01

This report describes the Emissions Audit carried out on a Biomass Combustor burning treated wood waste at the premises of a furniture manufacturer. The Biomass Combustor was tested in two firing modes; continuous fire and modulating fire. Combustion chamber temperatures and gas residence times were not measured. Boiler efficiencies were very good at greater than 75% in both tests. However, analysis of the flue gases indicated that improved efficiencies are possible. The average concentrations of CO (512mgm -3 ) and THC (34mgm -3 ) for Test 1 were high, indicating that combustion was poor. The combustor clearly does not meet the requirements of the Guidance Note for the Combustion of Wood Waste. CO 2 and O 2 concentrations were quite variable showing that combustion conditions were fairly unstable. Improved control of combustion should lead to acceptable emission concentrations. (Author)

Economical analyses of construction of a biomass boiler house

International Nuclear Information System (INIS)

Normak, A.

2002-01-01

To reduce the energy costs we can use cheaper fuel to fire our boiler. One of the cheapest fuels is wood biomass. It is very actual issue how to use cheaper wood biomass in heat generation to decrease energy costs and to increase biomass share in our energy balance. Before we decide to build biomass boiler house it is recommendable to analyse the economical situation and work out most profitable, efficient, reliable and ecological boiler plant design on particular conditions. The best way to perform the analyses is to use the economical model presented. It saves our time and gives objective evaluation to the project. (author)

Experimental study on dew point corrosion characteristics of the heating surface in a 65 t/h biomass-fired circulating fluidized bed boiler

International Nuclear Information System (INIS)

Wang, Yungang; Ma, Haidong; Liang, Zhiyuan; Chen, Heng; Zhao, Qinxin; Jin, Xin

2016-01-01

Highlights: • Dew point corrosion and ash deposit tests in a biomass-fired boiler were performed. • The XRD, XRF and SEM methods were used to analyze corrosion samples. • The deposits were made up of ash deposit layer, coupling layer and corrosion layer. • The metal matrix simultaneously confronted chlorine corrosion and oxygen corrosion. - Abstract: The dew point corrosion characteristics of the heating surface in a 65 t/h biomass-fired circulating fluidized bed (CFB) boiler were experimentally studied. The cross-sectional morphology and composition of the ash deposition were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence spectrum (XRF), respectively. The results showed that the test tube surface was covered by ash deposit layer, coupling layer and corrosion layer. The ash deposit layer and the coupling layer were prone to spall off together. The coupling layer consists of partial ash and corrosion products. The corrosion layer was mainly composed of chlorides (FeCl_3, FeCl_2, and FeOCl) and oxides (FeOOH, Fe_2O_3). With the increase of the tube wall temperature, the corrosion depth decreased dramatically and the dew point corrosion was alleviated efficiently. The metal matrix simultaneously suffered from chlorine corrosion and oxygen corrosion. As the tube wall temperature was above water dew point, the main corrosion mode was oxygen corrosion. As the tube wall temperature was below water dew point, the main corrosion mode was chlorine corrosion.

Characterization of biomass combustion at high temperatures based on an upgraded single particle model

International Nuclear Information System (INIS)

Li, Jun; Paul, Manosh C.; Younger, Paul L.; Watson, Ian; Hossain, Mamdud; Welch, Stephen

2015-01-01

Highlights: • High temperature rapid biomass combustion is studied based on single particle model. • Particle size changes in devolatilization and char oxidation models are addressed. • Time scales of various thermal sub-processes are compared and discussed. • Potential solutions are suggested to achieve better biomass co-firing performances. - Abstract: Biomass co-firing is becoming a promising solution to reduce CO 2 emissions, due to its renewability and carbon neutrality. Biomass normally has high moisture and volatile contents, complicating its combustion behavior, which is significantly different from that of coal. A computational fluid dynamics (CFD) combustion model of a single biomass particle is employed to study high-temperature rapid biomass combustion. The two-competing-rate model and kinetics/diffusion model are used to model biomass devolatilization reaction and char burnout process, respectively, in which the apparent kinetics used for those two models were from high temperatures and high heating rates tests. The particle size changes during the devolatilization and char burnout are also considered. The mass loss properties and temperature profile during the biomass devolatilization and combustion processes are predicted; and the timescales of particle heating up, drying, devolatilization, and char burnout are compared and discussed. Finally, the results shed light on the effects of particle size on the combustion behavior of biomass particle

Development of a dynamic drying model for for a combustion grate; Framtagande av en dynamisk torkmodell foer en foerbraenningsrost

Energy Technology Data Exchange (ETDEWEB)

Broden, Henrik; Ramstroem, Erik [TPS Termiska Processer AB, Nykoeping (Sweden)

2005-02-01

Combustion of wet wood fuel at high grate loading requires good control of the burnout position to avoid unacceptably high content of unburnt fuel in the ash. To control the burn-out position, control actions on the grate feeding must be made with sufficient range and anticipation. One way to improve the understanding of the dynamic fuel bed response on changes in control system parameters is mathematical modelling. The research task has been to develop a mathematical model of a drying fuel bed on a moving grate. The model includes a simplified description of drying, pyrolysis and char combustion and also pusher/grate movement and primary air flow/distribution. The objectives of the project have been to establish the most likely mechanism for drying and ignition of a wet fuel bed on a moving grate by the use of mathematical modelling and also to create a tool for simulation of control system step responses. The target group for the project are individuals working in the area of control system development of grate fired boilers. Three different assumptions on drying and ignition front propagation in a bio fuel bed with 50 and 53 % moisture have been modelled: 1. Drying and ignition from an underlying char layer in a co-current primary air flow 2. Drying and ignition from an overlaying char layer in counter-current primary air flow 3. Drying and ignition from both an underlying and overlaying char layer The model with drying and ignition driven by an underlying char layer is the projection, which gives the fastest and time-wise the most similar course to what one normally sees in grate fired boilers. The model with drying and ignition from above is not capable of upholding a stable diffusion controlled burning char layer since too small quantities of heat is transferred into the fuel bed. The model with drying and ignition from both directions results in similar combustion rate as the first model. The similar course of combustion is due to the energy for drying

Optical Fiber Grating based Sensors

DEFF Research Database (Denmark)

Michelsen, Susanne

2003-01-01

In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...... sampled gratings, was produced and investigated. It is based on the different temperature and strain response of these gratings. Both a transfer matrix method and an overlap calculation is performed to explain the sensor response. Another type of sensor is based on tuning and modulation of a laser...

Total peroxy nitrates and ozone production : analysis of forest fire plumes during BORTAS campaign

Science.gov (United States)

Busilacchio, Marcella; Di Carlo, Piero; Aruffo, Eleonora; Biancofiore, Fabio; Giammaria, Franco; Bauguitte, Stephane; Lee, James; Moller, Sarah; Lewis, Ally; Parrington, Mark; Palmer, Paul; Dari Salisburgo, Cesare

2014-05-01

The goal of this work is to investigate the connection between PNS and ozone within plumes emitted from boreal forest fires and the possible perturbation to oxidant chemistry in the troposphere. During the Aircraft campaign in Canada called BORTAS (summer 2011 ) were carried out several profiles from ground up to 10 km with the BAe-146 aircraft to observe the atmospheric composition inside and outside fire plumes. The BORTAS flights have been selected based on the preliminary studies of 'Plume identification', selecting those effected by Boreal forest fire emissions (CO > 200 ppbv). The FLAMBE fire counts were used concertedly with back trajectory calculations generated by the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to locate the sources of Boreal biomass burning.Profiles measured on board the BAe-146 aircraft are used to calculate the productions of PNs and O3 within the biomass burning plume. By selecting the flights that intercept the biomass burning plume, we evaluate the ratio between the ozone production and the PNs production within the plume. Analyzing this ratio it is possible to determine whether O3 production or PNs production is the dominant process in the biomass burning boreal plume detected during BORTAS campaign.

Adapting fire management to future fire regimes: impacts on boreal forest composition and carbon balance in Canadian National Parks

Science.gov (United States)

de Groot, W. J.; Flannigan, M. D.; Cantin, A.

2009-04-01

The effects of future fire regimes altered by climate change, and fire management in adaptation to climate change were studied in the boreal forest region of western Canada. Present (1975-90) and future (2080-2100) fire regimes were simulated for several National Parks using data from the Canadian (CGCM1) and Hadley (HadCM3) Global Climate Models (GCM) in separate simulation scenarios. The long-term effects of the different fire regimes on forests were simulated using a stand-level, boreal fire effects model (BORFIRE). Changes in forest composition and biomass storage due to future altered fire regimes were determined by comparing current and future simulation results. This was used to assess the ecological impact of altered fire regimes on boreal forests, and the future role of these forests as carbon sinks or sources. Additional future simulations were run using adapted fire management strategies, including increased fire suppression and the use of prescribed fire to meet fire cycle objectives. Future forest composition, carbon storage and emissions under current and adapted fire management strategies were also compared to determine the impact of various future fire management options. Both of the GCM's showed more severe burning conditions under future fire regimes. This includes fires with higher intensity, greater depth of burn, greater total fuel consumption and shorter fire cycles (or higher rates of annual area burned). The Canadian GCM indicated burning conditions more severe than the Hadley GCM. Shorter fire cycles of future fire regimes generally favoured aspen, birch, and jack pine because it provided more frequent regeneration opportunity for these pioneer species. Black spruce was only minimally influenced by future fire regimes, although white spruce declined sharply. Maintaining representation of pure and mixed white spruce ecosystems in natural areas will be a concern under future fire regimes. Active fire suppression is required in these areas. In

Biomass based energy. A review on raw materials and processing methods; Energie aus Biomasse. Eine Uebersicht ueber Rohstoffe und Verfahren

Energy Technology Data Exchange (ETDEWEB)

Woellauer, P

2007-07-01

The book reviews the variety of biogenic raw materials and the technologically important biomass conversion techniques. The chapter on the different kinds of biomass includes a) wood from forestry, landscape culturing and saw mills, bark and old wood; b) plants (corn, miscanthus, cannabis, wheat, rye, sugar beets, grass, rape, etc.), residuals and wastes (straw, liquid manure, slaughthouse wastes, kitchen wastes, sewage sludge, others). The chapter on biomass conversion processing discusses combustion, oxidation in spercritical water, gasification and reforming, fermentation, extrusion or extraction, and downstream processes. The chapter on biomass based electricity and mechanical energy includes refrigeration engineering, direct utilization: Otto engines, Diesel engines, microgas turbine fuel cells, and heat processing: Striling engine, vapour turbine, ORC turbine, externally fired gas turbine, and the Kalina process.

FY 2000 Report on survey results. Curtailment of the carbon dioxide emission by effective use of woody biomass system waste; 2000 nendo mokushitsu biomass kei haikibutsu no yuko riyo ni yoru nisanka tanso haishutsu no sakugen

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

It is estimated that the woody biomass resources in Japan total 42.70 million t/y on a dry basis (indigenous production: 20.00 million t/y), which corresponds to 18.00 million t/y as oil. This project studies effective utilization of low-quality biomass resources now discarded, e.g., thinning materials and demolition woods, by reference to biomass utilization pursued in European and North American countries. The study activities cover the 3 areas of woody biomass wastes, current status of biomass utilization technologies in the overseas countries, and feasibility of introduction of the utilization technologies, after investigating necessity of abatement of the green-effect gases, current status of energy demands and policies, and woody biomass. Utilization of biomass resources for low-temperature heat purposes, which is the central issue in Japan, is not well established both technologically and politically. Moreover, the biomass resources are not exposed to price competition. Based on these premises, a total of 6 scenarios are proposed to promote utilization of biomass resources, including power/heat co-generation at a wood processing center, and dual firing at existing coal-fired boilers. (NEDO)

Wildland fire emissions, carbon, and climate: Modeling fuel consumption

Science.gov (United States)

Roger D. Ottmar

2014-01-01

Fuel consumption specifies the amount of vegetative biomass consumed during wildland fire. It is a two-stage process of pyrolysis and combustion that occurs simultaneously and at different rates depending on the characteristics and condition of the fuel, weather, topography, and in the case of prescribed fire, ignition rate and pattern. Fuel consumption is the basic...

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

International Nuclear Information System (INIS)

Wang, Changbo; Zhang, Lixiao; Chang, Yuan; Pang, Mingyue

2015-01-01

To gain a better understanding of the options of biomass power generation in China, this study presented an integrated energy, environmental, and economic evaluation for Salix in China, and a typical Salix direct-fired power generation system (SDPGS) in Inner Mongolia was selected for case study. A tiered hybrid life cycle assessment (LCA) model was developed to calculate the “planting-to-wire” (PTW) energy consumption, greenhouse gas (GHG) emissions, and economic cost and profit of the SDPGS, including feedstock cultivation, power plant construction and operation, and on-grid price with/without government subsidies. The results show that the PTW energy consumption and GHG emissions of Salix are 0.8 MJ/kWh and 114 g CO 2 -eq/kWh, respectively, indicating an energy payback time (EPBT) of 3.2 years. The SDPGS is not economically feasible without government subsidies. The PTW costs are dominated by feedstock cultivation. The energy saving and GHG mitigation benefits are still robust, even when the power plant runs at only 60% design capacity. For future development of biomass power in China, scientific planning is necessary to guarantee a sufficient feedstock supply. In addition, technology progress, mature industrial chains, and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward. -- Highlights: •A hybrid LCA model was used to evaluate overall performance of the SDPGS. •On-site processes dominate the “planting-to-wire” footprints. •The energy saving and GHG mitigation benefits of the SDPGS are robust. •The economic profit of the SDPGS is feeble without government subsidies. •Generating efficiency promotion has a comprehensive positive effect on the system

Avoided emissions of a fuel-efficient biomass cookstove dwarf embodied emissions

Directory of Open Access Journals (Sweden)

D.L. Wilson

2016-06-01

Full Text Available Three billion people cook their food on biomass-fueled fires. This practice contributes to the anthropogenic radiative forcing. Fuel-efficient biomass cookstoves have the potential to reduce CO2-equivalent emissions from cooking, however, cookstoves made from modern materials and distributed through energy-intensive supply chains have higher embodied CO2-equivalent than traditional cookstoves. No studies exist examining whether lifetime emissions savings from fuel-efficient biomass cookstoves offset embodied emissions, and if so, by what margin. This paper is a complete life cycle inventory of “The Berkeley–Darfur Stove,” disseminated in Sudan by the non-profit Potential Energy. We estimate the embodied CO2-equivalent in the cookstove associated with materials, manufacturing, transportation, and end-of-life is 17 kg of CO2-equivalent. Assuming a mix of 55% non-renewable biomass and 45% renewable biomass, five years of service, and a conservative 35% reduction in fuel use relative to a three-stone fire, the cookstove will offset 7.5 tonnes of CO2-equivalent. A one-to-one replacement of a three-stone fire with the cookstove will save roughly 440 times more CO2-equivalent than it “costs” to create and distribute. Over its five-year life, we estimate the total use-phase emissions of the cookstove to be 13.5 tonnes CO2-equivalent, and the use-phase accounts for 99.9% of cookstove life cycle emissions. The dominance of use-phase emissions illuminate two important insights: (1 without a rigorous program to monitor use-phase emissions, an accurate estimate of life cycle emissions from biomass cookstoves is not possible, and (2 improving a cookstove's avoided emissions relies almost exclusively on reducing use-phase emissions even if use-phase reductions come at the cost of substantially increased non-use-phase emissions.

An Overview of Recent Geostationary Fire Monitoring Activities and Applications in the Western Hemisphere

Science.gov (United States)

McRae, D. J.; Conard, S. G.; Ivanova, G. A.; Sukhinin, A. I.; Hao, W. M.; Koutzenogii, K. P.; Prins, E. M.; Schmidt, C. C.; Feltz, J. M.

2002-05-01

Over the past twenty years the international scientific research and environmental monitoring communities have recognized the vital role environmental satellites can play in detecting and monitoring active fires both regionally and around the globe for hazards applications and to better understand the extent and impact of biomass burning on the global environment. Both groups have stressed the importance of utilizing operational satellites to produce routine fire products and to ensure long-term stable records of fire activity for applications such as land-use/land cover change analyses and global climate change research. The current NOAA GOES system provides the unique opportunity to detect fires throughout the Western Hemisphere every half-hour from a series of nearly identical satellites for a period of 15+ years. This presentation will provide an overview of the GOES biomass burning monitoring program at UW-Madison Cooperative Institute for Meteorological Satellite Studies (CIMSS) with an emphasis on recent applications of the new GOES Wildfire Automated Biomass Burning Algorithm (WF_ABBA). For the past 8 years, CIMSS has utilized the GOES-8 imager to monitor biomass burning trends in South America. Since September 2000, CIMSS has been producing half-hourly fire products in real-time for most of the Western Hemisphere. The WF_ABBA half-hourly fire product is providing new insights into diurnal, spatial, seasonal and interannual fire dynamics in North, Central, and South America. In North America these products are utilized to detect and monitor wildfires in northerly and remote locations. In South America the diurnal GOES fire product is being used as an indicator of land-use and land-cover change and carbon dynamics along the borders between Brazil, Peru, and Bolivia. The Navy is assimilating the Wildfire ABBA fire product into the Navy Aerosol Analysis and Prediction System (NAAPS) to analyze and predict aerosol loading and transport as part of the NASA

Energy production from marine biomass (Ulva lactuca)

Energy Technology Data Exchange (ETDEWEB)

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

2011-11-15

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

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

Science.gov (United States)

Chen, Xuexia; Liu, Shuguang; Zhu, Zhiliang; Vogelmann, James E.; Li, Zhengpeng; Ohlen, Donald O.

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 fire-induced 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

Apodized grating coupler using fully-etched nanostructures

International Nuclear Information System (INIS)

Wu Hua; Li Chong; Guo Xia; Li Zhi-Yong

2016-01-01

A two-dimensional apodized grating coupler for interfacing between single-mode fiber and photonic circuit is demonstrated in order to bridge the mode gap between the grating coupler and optical fiber. The grating grooves of the grating couplers are realized by columns of fully etched nanostructures, which are utilized to digitally tailor the effective refractive index of each groove in order to obtain the Gaussian-like output diffractive mode and then enhance the coupling efficiency. Compared with that of the uniform grating coupler, the coupling efficiency of the apodized grating coupler is increased by 4.3% and 5.7%, respectively, for the nanoholes and nanorectangles as refractive index tunes layer. (paper)

Switchable Bragg gratings

DEFF Research Database (Denmark)

Marckmann, Carl Johan

2003-01-01

Research Center (MIC) at the Technical University of Denmark. The Bragg gratings were fabricated at COM using UV irradiation of the planar waveguides using the phase mask method. The induction of a frozen-in DC electric field into the samples was performed by thermal poling of the Bragg gratings...... layers, it becam possible to investigate the symmetry properties of the third-order nonlinearities. Contrary to the expectations for an amorphous material, the measurements indicated an almost polarization independent third-order nonlinearity - the most probable explanation being electrostriction......The subject of this ph.d. thesis was the development of an electrically switchable Bragg grating made in an optical waveguide using thermal poling to be applied within optical telecommunication systems. The planar waveguides used in this thesis were fabricated at the Micro- and Nanotechnology...

Nanoporous Polymeric Grating-Based Biosensors

KAUST Repository

Gao, Tieyu; Hsiao, Vincent; Zheng, Yue Bing; Huang, Tony Jun

2012-01-01

We demonstrate the utilization of an interferometrically created nanoporous polymeric gratings as a platform for biosensing applications. Aminopropyltriethoxysilane (APTES)-functionalized nanoporous polymeric gratings was fabricated by combining holographic interference patterning and APTES-functionalization of pre-polymer syrup. The successful detection of multiple biomolecules indicates that the biofunctionalized nanoporous polymeric gratings can act as biosensing platforms which are label-free, inexpensive, and applicable as high-throughput assays. Copyright © 2010 by ASME.

Nanoporous Polymeric Grating-Based Biosensors

KAUST Repository

Gao, Tieyu

2012-05-02

We demonstrate the utilization of an interferometrically created nanoporous polymeric gratings as a platform for biosensing applications. Aminopropyltriethoxysilane (APTES)-functionalized nanoporous polymeric gratings was fabricated by combining holographic interference patterning and APTES-functionalization of pre-polymer syrup. The successful detection of multiple biomolecules indicates that the biofunctionalized nanoporous polymeric gratings can act as biosensing platforms which are label-free, inexpensive, and applicable as high-throughput assays. Copyright © 2010 by ASME.

Deformation and Heat Transfer on Three Sides Protected Beams under Fire Accident

Science.gov (United States)

Imran, M.; Liew, M. S.; Garcia, E. M.; Nasif, M. S.; Yassin, A. Y. M.; Niazi, U. M.

2018-04-01

Fire accidents are common in oil and gas industry. The application of passive fire protection (PFP) is a costly solution. The PFP is applied only on critical structural members to optimise project cost. In some cases, beams cannot be protected from the top flange in order to accommodate for the placement of pipe supports and grating. It is important to understand the thermal and mechanical response of beam under such condition. This paper discusses the response of steel beam under ISO 834 fire protected, unprotected and three sides protected beams. The model validated against an experimental study. The experimental study has shown good agreement with FE model. The study revealed that the beams protected from three sides heat-up faster compare to fully protected beam showing different temperature gradient. However, the affects load carrying capacity are insignificant under ISO 834 fire.

Peat Biomass Smoke Particle Exposure in Rats Decreases ...

Science.gov (United States)

Wildland fires, favored by prolonged drought and rising temperatures, generate significant amounts of ambient particulate matter (PM), which has been linked to adverse health outcomes. The eastern North Carolina peat fires of Pocosin Lake in 2008 and Pains Bay in 2011 were some of the more prominent recent wildland fires and were associated with increased cardiovascular hospitalizations. The biological impacts of peat biomass emissions and the specific mechanisms driving these responses are unclear. The purpose of this study was to investigate the cardiopulmonary responses of peat biomass smoke exposure in rats. We hypothesized that PM exposure would dose-dependently alter cardiopulmonary function. Male Sprague-Dawley rats were exposed to 30 µg (Lo PM) or 300 µg (Hi PM) of peat biomass smoke PM extracts suspended in 200 µL of saline, or saline vehicle alone by oropharyngeal aspiration (OA). Immediately following OA rats were placed in a whole-body plethysmograph and ventilatory data were recorded for 12 minutes. One day following OA, rats were anesthetized with isoflurane for ultrasound assessment of cardiovascular function. Hi PM caused decreases in expiratory timing as early as 4-6 minutes after exposure relative to Lo PM (p = 0.02) and Vehicle (p= 0.06), which resolved shortly thereafter. One day after OA, ultrasounds revealed that Hi PM exposure increased end diastolic volume (EDV) by 16% (p = 0.03) over Vehicle and 13% (p = 0.06) over Lo PM. In addition,

The interactive effects of fire and diversity on short-term responses of ecosystem processes in experimental mediterranean grasslands.

Science.gov (United States)

Dimitrakopoulos, Panayiotis G; Siamantziouras, Akis-Stavros D; Galanidis, Alexandros; Mprezetou, Irene; Troumbis, Andreas Y

2006-06-01

We conducted a field experiment using constructed communities to test whether species richness contributed to the maintenance of ecosystem processes under fire disturbance. We studied the effects of diversity components (i.e., species richness and species composition) upon productivity, structural traits of vegetation, decomposition rates, and soil nutrients between burnt and unburnt experimental Mediterranean grassland communities. Our results demonstrated that fire and species richness had interactive effects on aboveground biomass production and canopy structure components. Fire increased biomass production of the highest-richness communities. The effects of fire on aboveground biomass production at different levels of species richness were derived from changes in both vertical and horizontal canopy structure of the communities. The most species-rich communities appeared to be more resistant to fire in relation to species-poor ones, due to both compositional and richness effects. Interactive effects of fire and species richness were not important for belowground processes. Decomposition rates increased with species richness, related in part to increased levels of canopy structure traits. Fire increased soil nutrients and long-term decomposition rate. Our results provide evidence that composition within richness levels had often larger effects on the stability of aboveground ecosystem processes in the face of fire disturbance than species richness per se.

Encapsulation process for diffraction gratings.

Science.gov (United States)

Ratzsch, Stephan; Kley, Ernst-Bernhard; Tünnermann, Andreas; Szeghalmi, Adriana

2015-07-13

Encapsulation of grating structures facilitates an improvement of the optical functionality and/or adds mechanical stability to the fragile structure. Here, we introduce novel encapsulation process of nanoscale patterns based on atomic layer deposition and micro structuring. The overall size of the encapsulated structured surface area is only restricted by the size of the available microstructuring and coating devices; thus, overcoming inherent limitations of existing bonding processes concerning cleanliness, roughness, and curvature of the components. Finally, the process is demonstrated for a transmission grating. The encapsulated grating has 97.5% transmission efficiency in the -1st diffraction order for TM-polarized light, and is being limited by the experimental grating parameters as confirmed by rigorous coupled wave analysis.

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

DEFF Research Database (Denmark)

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

2013-01-01

and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools....... The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This paper provides...... research has provided results with implications for operation of milling and burner equipment, appropriate fuel mixing strategies, minimization of ash deposit formation and corrosion, minimization of NO formation, appropriate operation of SCR catalyst equipment and utilization of residual products...

Extending the capabilities of CFD codes to assess ash related problems

DEFF Research Database (Denmark)

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

2004-01-01

This paper discusses the application of FLUENT? in theanalysis of grate-fired biomass boilers. A short description of theconcept used to model fuel conversion on the grate and the couplingto the CFD code is offered. The development and implementation ofa CFD-based deposition model is presented...... in the reminder of thepaper. The growth of deposits on furnace walls and super heatertubes is treated including the impact on heat transfer rates determinedby the CFD code. Based on the commercial CFD code FLUENT?,the overall model is fully implemented through the User DefinedFunctions. The model is configured...

Input of biomass in power plants for power generation. Calculation of the financial gap. Final report

International Nuclear Information System (INIS)

Van Tilburg, X.; De Vries, H.J.; Pfeiffer, A.E.; Cleijne, J.W.

2005-09-01

The Ministry of Economic Affairs has requested ECN and KEMA to answer two questions. (1) Are the costs and benefits of projects in which wood-pellets are co-fired in a coal fired power plant representative for those of bio-oil fueled co-firing projects in a gas fired plant?; and (2) Are new projects representative for existing projects? To answer these questions, ECN and KEMA have calculated the financial gaps in six different situations: co-firing bio-oil in a gas fired power plant; co-firing bio-oil in a coal fired power plant; gasification of solid biomass; co-firing wood pellets in a coal fired power plant; co-firing agricultural residues in a coal fired power plant; and co-firing waste wood (A- and B-grade) in a coal fired power plant. The ranges and reference cases show that co-firing bio-oil on average has a smaller financial gap than the solid biomass reference case. On average it can also be concluded that when using waste wood or agro-residues, the financial gaps are smaller. Based on these findings it is concluded that: (1) The reference case of co-firing wood pellets in a coal fired power plant are not representative for bio-fuel options. A new category for bio-oil options seems appropriate; and (2) The financial gap of new projects as calculated in November 2004, is often higher then the ranges for existing projects indicate [nl

An elastomeric grating coupler

NARCIS (Netherlands)

Kocabas, A.; Ay, F.; Dana, A.; Aydinli, A.

We report on a novel nondestructive and reversible method for coupling free space light to planar optical waveguides. In this method, an elastomeric grating is used to produce an effective refractive index modulation on the surface of the optical waveguide. The external elastomeric grating binds to

Bragg gratings in Topas

DEFF Research Database (Denmark)

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

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

PRODUCTION OF NEW BIOMASS/WASTE-CONTAINING SOLID FUELS

Energy Technology Data Exchange (ETDEWEB)

David J. Akers; Glenn A. Shirey; Zalman Zitron; Charles Q. Maney

2001-04-20

CQ Inc. and its team members (ALSTOM Power Inc., Bliss Industries, McFadden Machine Company, and industry advisors from coal-burning utilities, equipment manufacturers, and the pellet fuels industry) addressed the objectives of the Department of Energy and industry to produce economical, new solid fuels from coal, biomass, and waste materials that reduce emissions from coal-fired boilers. This project builds on the team's commercial experience in composite fuels for energy production. The electric utility industry is interested in the use of biomass and wastes as fuel to reduce both emissions and fuel costs. In addition to these benefits, utilities also recognize the business advantage of consuming the waste byproducts of customers both to retain customers and to improve the public image of the industry. Unfortunately, biomass and waste byproducts can be troublesome fuels because of low bulk density, high moisture content, variable composition, handling and feeding problems, and inadequate information about combustion and emissions characteristics. Current methods of co-firing biomass and wastes either use a separate fuel receiving, storage, and boiler feed system, or mass burn the biomass by simply mixing it with coal on the storage pile. For biomass or biomass-containing composite fuels to be extensively used in the U.S., especially in the steam market, a lower cost method of producing these fuels must be developed that includes both moisture reduction and pelletization or agglomeration for necessary fuel density and ease of handling. Further, this method of fuel production must be applicable to a variety of combinations of biomass, wastes, and coal; economically competitive with current fuels; and provide environmental benefits compared with coal. Notable accomplishments from the work performed in Phase I of this project include the development of three standard fuel formulations from mixtures of coal fines, biomass, and waste materials that can be used in

Small-scale biomass CHP using gasa turbines: a scoping study

International Nuclear Information System (INIS)

James, D.W.; Landen, R.

1996-01-01

Various options for small-scale (up to 250 KWe) Combined Heat and Power (CHP) plants evaluated in this scoping study. Plants using small gas turbines, and able to use biomass fuels when available are included. Three detailed case studies of small-scale biomass CHP plants are compared to match specific technical options with customer requirements. The commercial development of such biomass-fired CHP units, using gas turbines, is shown to be economically viable depending on fuel costs and the continuation of existing financial incentives. (UK)

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

Directory of Open Access Journals (Sweden)

Smajevic Izet

2012-01-01

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

Thermal and Structural Analysis of FIMS Grating

Directory of Open Access Journals (Sweden)

K.-I. Seon

2001-06-01

Full Text Available Far ultraviolet IMaging Spectrograph (FIMS should be designed to maintain its structural stability and to minimize optical performance degradation in launch and in operation enviroments. The structural and thermal analyzes of grating and grating mount system, which are directly related to FIMS optical performance, was performed using finite element method. The grating mount was made to keep the grating stress down, while keeping the natural frequency of the grating mount higher than 100 Hz. Transient and static thermal analyzes were also performed and the results shows that the thermal stress on the grating can be attenuated sufficiently The optical performance variation due to temperature variation was within the allowed range.

How important is biomass burning in Canada to mercury contamination?

Science.gov (United States)

Fraser, Annemarie; Dastoor, Ashu; Ryjkov, Andrei

2018-05-01

Wildfire frequency has increased in past four decades in Canada and is expected to increase in future as a result of climate change (Wotton et al., 2010). Mercury (Hg) emissions from biomass burning are known to be significant; however, the impact of biomass burning on air concentration and deposition fluxes in Canada has not been previously quantified. We use estimates of burned biomass from FINN (Fire INventory from NCAR) and vegetation-specific emission factors (EFs) of mercury to investigate the spatiotemporal variability of Hg emissions in Canada. We use Environment and Climate Change Canada's GEM-MACH-Hg (Global Environmental Multi-scale, Modelling Air quality and Chemistry model, mercury version) to quantify the impact of biomass burning in Canada on spatiotemporal variability of air concentrations and deposition fluxes of mercury in Canada. We use North American gaseous elemental mercury (GEM) observations (2010-2015), GEM-MACH-Hg, and an inversion technique to optimize the EFs for GEM for five vegetation types represented in North American fires to constrain the biomass burning impacts of mercury. The inversion results suggest that EFs representing more vegetation types - specifically peatland - are required. This is currently limited by the sparseness of measurements of Hg from biomass burning plumes. More measurements of Hg concentration in the air, specifically downwind of fires, would improve the inversions. We use three biomass burning Hg emissions scenarios in Canada to conduct three sets of model simulations for 2010-2015: two scenarios where Hg is emitted only as GEM using literature or optimized EFs and a third scenario where Hg is emitted as GEM using literature EFs and particle bound mercury (PBM) emitted using the average GEM/PBM ratio from lab measurements. The three biomass burning emission scenarios represent a range of possible values for the impacts of Hg emissions from biomass burning in Canada on Hg concentration and deposition. We find

Fuel characteristics and trace gases produced through biomass burning

Directory of Open Access Journals (Sweden)

BAMBANG HERO SAHARJO

2010-01-01

Full Text Available Saharjo BH, Sudo S, Yonemura S, Tsuruta H (2010 Fuel characteristics and trace gases produced through biomass burning. Biodiversitas 11: 40-45. Indonesian 1997/1998 forest fires resulted in forest destruction totally 10 million ha with cost damaged about US$ 10 billion, where more than 1 Gt CO2 has been released during the fire episode and elevating Indonesia to one of the largest polluters of carbon in the world where 22% of world’s carbon dioxide produced. It has been found that 80-90% of the fire comes from estate crops and industrial forest plantation area belongs to the companies which using fire illegally for the land preparation. Because using fire is cheap, easy and quick and also support the companies purpose in achieving yearly planted area target. Forest management and land use practices in Sumatra and Kalimantan have evolved very rapidly over the past three decades. Poor logging practices resulted in large amounts of waste will left in the forest, greatly elevating fire hazard. Failure by the government and concessionaires to protect logged forests and close old logging roads led to and invasion of the forest by agricultural settlers whose land clearances practices increased the risk of fire. Several field experiments had been done in order to know the quality and the quantity of trace produced during biomass burning in peat grass, peat soil and alang-alang grassland located in South Sumatra, Indonesia. Result of research show that different characteristics of fuel burned will have the different level also in trace gasses produced. Peat grass with higher fuel load burned produce more trace gasses compared to alang-alang grassland and peat soil.

Evaluating a biomass resource: The TVA region-wide biomass resource assessment model

International Nuclear Information System (INIS)

Downing, M.; Graham, R.L.

1993-01-01

Wood is an alterative fuel for electric power generation at coal-fired plants in the Tennessee Valley Authority (TVA) region. Short rotation wood energy crops (SRWC) could provide a source of this woody biomass. However, the economic and supply structures of SRWC markets have not been established. Establishing the likely price and supply of SRWC biomass in a region is a complex task because biomass is not an established commodity as are oil, natural gas and coal. In this study we project the cost and supply of short-rotation woody biomass for the TVA region -- a 276 county area that includes all of Tennessee and portions of 10 contiguous states in the southeastern United States. Projected prices and quantities of SRWC are assumed to be a function of the amount and quality of crop and pasture land available in a region. expected SRWC yields and production costs on differing soils and land types, and the profit that could be obtained from current conventional crop production on these same lands. Results include the supply curve of SRWC biomass that is projected to be available from the entire region, the amount and location of crop and pasture land that would be used, and the conventional agricultural crops that would be displaced as a function of SRWC production. Finally, we show the results of sensitivity analysis on the projected cost and supply of SRWC biomass. In particular, we examine the separate impacts of varying SRWC production yields

Embedded high-contrast distributed grating structures

Science.gov (United States)

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.

Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

Directory of Open Access Journals (Sweden)

Antonio Rigueiro-Rodríguez

2012-02-01

Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

Accounting for biomass carbon stock change due to wildfire in temperate forest landscapes in Australia.