Wood pellet use in Sweden. A systems approach to the residential sector

International Nuclear Information System (INIS)

Vinterbaeck, Johan

2000-01-01

This empirically based thesis deals with a biofuel market in a systems context with focus on Sweden. Fuel pellets is a new consumer market for wood products. Initially used mainly by large-scale heating plants, wood pellets expanded into the Swedish residential heating market in the mid 1990s. The overall aim of this work is to provide a deeper understanding of the system for small-scale use of densified wood fuels. The objective was to provide a mapping and logistic analysis of fuel and delivery chains primarily for wood pellets. The description includes both technical as well as economic and organisational aspects. The thesis in particular investigates (i) experience from practical densification operations in the past, (ii) wood pellet retailers in Sweden, (iii) wood pellet consumers in Austria, Sweden and the United States, (iv) imports of wood pellets, and (v) forecasting of pellet consumption and inventory management for wood pellet distributors. Previous international studies revealed that the availability of cheap raw materials for fuel production and the price and availability of the most important competing fuels: coal, oil and natural gas were important factors that have guided production and use of densified wood and bark fuels. A major network of wood pellet distributors was mapped. It was concluded from a survey to these retailers that the Swedish residential market was now firmly in place and that the price of wood pellets was competitive with prices of traditional national fuels. A majority of pellet users in Austria, Sweden and the United States were pleased with pellet heating. One way to improve pellet distribution systems would be to optimise inventory management. An internal model for optimising inventory management, Pell-Sim, was constructed. For Sweden, wood pellets in 1997 represented the second most traded biofuel assortment, with 4.35 PJ or 18% of the total biofuel imports. Contrary to trade with other biofuel assortments, wood pellet trade

Wood pellets, what else? Greenhouse gas parity times of European electricity from wood pellets produced in the south-eastern United States using different softwood feedstocks

Energy Technology Data Exchange (ETDEWEB)

Hanssen, Steef V. [Radboud Univ., Nijmegen (Netherlands). Dept. of Environmental Science, Faculty of Science; Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences; Duden, Anna S. [Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences; Junginger, Martin [Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences; Dale, Virginia H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division, Center for BioEnergy Sustainability; van der Hilst, Floor [Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences

2016-12-29

Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas (GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are reduced and on what timescale, we construct the GHG balance of wood-pellet electricity. This GHG balance consists of supply chain and combustion GHG emissions, carbon sequestration during biomass growth, and avoided GHG emissions through replacing fossil electricity. We investigate wood pellets from four softwood feedstock types: small roundwood, commercial thinnings, harvest residues, and mill residues. Per feedstock, the GHG balance of wood-pellet electricity is compared against those of alternative scenarios. Alternative scenarios are combinations of alternative fates of the feedstock material, such as in-forest decomposition, or the production of paper or wood panels like oriented strand board (OSB). Alternative scenario composition depends on feedstock type and local demand for this feedstock. Results indicate that the GHG balance of wood-pellet electricity equals that of alternative scenarios within 0 to 21 years (the GHG parity time), after which wood-pellet electricity has sustained climate benefits. Parity times increase by a maximum of twelve years when varying key variables (emissions associated with paper and panels, soil carbon increase via feedstock decomposition, wood-pellet electricity supply chain emissions) within maximum plausible ranges. Using commercial thinnings, harvest residues or mill residues as feedstock leads to the shortest GHG parity times (0-6 years) and fastest GHG benefits from wood-pellet electricity. Here, we find shorter GHG parity times than previous studies, for we use a novel approach that differentiates feedstocks and considers alternative scenarios based on (combinations of) alternative feedstock fates, rather than on alternative land

Pellet wood gasification boiler / Combination boiler. Market review. 7. ed.; Scheitholzvergaser-/Kombikessel. Marktuebersicht

Energy Technology Data Exchange (ETDEWEB)

Uth, Joern

2010-08-15

In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) report on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

Market review. Pellet wood gasification boiler / combination boiler. 8. ed.; Marktuebersicht. Scheitholzvergaser-/Kombikessel

Energy Technology Data Exchange (ETDEWEB)

Uth, Joern

2012-01-15

In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) reports on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

Science.gov (United States)

Guo, Feihong; Zhong, Zhaoping

2018-08-01

This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of laboratory studies on the off-grassing of wood pellets

Energy Technology Data Exchange (ETDEWEB)

Shankar Tumuluru, Jaya; Kuang, X.; Sokhansanj, S.; Lim, C.J.; Bi, T.; Melin, S.

2010-07-01

The use of wood pellets as fuel has been steadily increasing, and with it the problem of safe storage. The aim of this study was to determine the effect of storage temperature on the emission of off-gases and on wood pellet properties, such as moisture content, durability and density. Three sealed containers were developed to store and maintain wood pellets at a fixed temperature; they then measured the off-gases concentrations in the containers and analyzed the changes in the wood pellets properties. The containers developed were proved to be efficient in controlling the temperature and could be thus reused for further studies. The results showed that the temperature had an important effect on the wood pellets properties; and in the meantime an important increase in off-gases emissions was observed when the storage temperature was increased. This study successfully correlated emissions of off-gases and modifications in wood pellets properties with storage temperature, these results must be taken into account when designing a wood pellet storage facility.

Torrefaction of wood pellets: New solutions

Science.gov (United States)

Zaichenko, V. M.; Shterenberg, V. Ya.

2017-10-01

The current state of the market of conventional and torrefied wood pellets and the trends of its development have been analyzed. The advantages and disadvantages of pellets of both types have been compared with other alternative fuels. The consumer segment in which wood pellets are the most competitive has been determined. The original torrefaction technology using exhaust gas heat from a standard gas engine that was developed at the Joint Institute for High Technologies and the scheme of an experimental unit for the elaboration of the technology have been presented. The scheme of the combined operation of a torrefaction unit and a standard hot water boiler, which makes it possible to utilize the heat of exhaust steam-and-gas products of torrefaction with the simultaneous prevention of emissions of harmful substances into the environment, has been proposed. The required correlation between the capacity of the torrefaction unit and the heating boiler house has been estimated for optimal operation under the conditions of the isolated urban village in a region that is distant from the areas of extraction of traditional fuels and, at the same time, has quite sufficient resources of raw materials for the production of wood pellets.

Wood pellet market and trade: A global perspective

NARCIS (Netherlands)

Goh, C.S.; Cocchi, M.; Junginger, H.M.; Marchal, D.; Thrän, D.; Hennig, C.; Heinimo, J.; Nikolaisen, L.; Schouwenberg, P.P.; Bradley, D.; Hess, R.F.; Jacobson, J.; Ovard, L.; Deutmeyer, M.

2013-01-01

This perspective provides an overview of wood pellet markets in a number of countries of high signifi cance, together with an inventory of market factors and relevant past or existing policies. In 2010, the estimated global wood pellet production and consumption were close to 14.3 Mt (million

International Trade of Wood Pellets (Brochure)

Energy Technology Data Exchange (ETDEWEB)

2013-05-01

The production of wood pellets has increased dramatically in recent years due in large part to aggressive emissions policy in the European Union; the main markets that currently supply the European market are North America and Russia. However, current market circumstances and trade dynamics could change depending on the development of emerging markets, foreign exchange rates, and the evolution of carbon policies. This fact sheet outlines the existing and potential participants in the wood pellets market, along with historical data on production, trade, and prices.

The wood pellet market in Austria: A structural market model analysis

International Nuclear Information System (INIS)

Kristöfel, Christa; Strasser, Christoph; Schmid, Erwin; Morawetz, Ulrich B.

2016-01-01

EU bioenergy policies and oil price hikes have resulted in a significant increase of installed pellet boilers for residential heating. Hence, European demand for wood pellets has been growing faster and more steadily than supply leading to rising market prices in recent years. This article presents an econometric analysis of demand and supply of wood pellets in the residential heating sector in Austria, one of the most dynamic markets for residential pellets. Annual and monthly time series data between 2000 and 2014 are used in a two-stage least-squares (2SLS) regression to estimate supply and demand elasticities of wood pellets. In all model specifications, pellets demand is found to be inelastic (from −0.66 to −0.76) and pellets supply unit-elastic (from 1.03 to 1.18). Thus, consumers are highly exposed to price changes resulting from supply shocks. Policies which support investments in pellet boilers will shift the demand of wood pellets and likely leading to higher prices for consumers. - Highlights: • Characterisation of the European pellet market. • A structural market model for wood pellets in Austria. • Estimation of supply and demand price elasticities using a two-stage least-squares (2SLS) regression. • Pellets demand is found to be inelastic and pellets supply unit-elastic in the short run. • Policies stimulating demand will likely increase pellet and sawmill by-product prices.

Energy wood. Part 2b: Wood pellets and pellet space-heating systems; Holzenergie Teil 2b: Holzpellets und Pelletheizungen / Energie du bois Partie 2b: Granules de bois et installations de chauffage a granules de bois

Energy Technology Data Exchange (ETDEWEB)

Nussbaumer, T. [Verenum, Zuerich (Switzerland)

2002-07-01

The paper gives an overview on pellet utilization including all relevant process steps: Potential and properties of saw dust as raw material, pellet production with drying and pelletizing, standardization of wood pellets, storage and handling of pellets, combustion of wood pellets in stoves and boilers and applications for residential heating. In comparison to other wood fuels, wood pellets show several advantages: Low water content and high heating value, high energy density, and homogeneous properties thus enabling stationary combustion conditions. However, quality control is needed to ensure constant properties of the pellets and to avoid the utilization of contaminated raw materials for the pellet production. Typical data of efficiencies and emissions of pellet stoves and boilers are given and a life cycle analysis (LCA) of wood pellets in comparison to log wood and wood chips is described. The LCA shows that wood pellets are advantageous thanks to relatively low emissions. Hence, the utilization of wood pellet is proposed as a complementary technology to the combustion of wood chips and log wood. Finally, typical fuel cost of wood pellets in Switzerland are given and compared with light fuel oil. (author)

Respiratory symptoms and lung function in relation to wood dust and monoterpene exposure in the wood pellet industry.

Science.gov (United States)

Löfstedt, Håkan; Hagström, Katja; Bryngelsson, Ing-Liss; Holmström, Mats; Rask-Andersen, Anna

2017-06-01

Wood pellets are used as a source of renewable energy for heating purposes. Common exposures are wood dust and monoterpenes, which are known to be hazardous for the airways. The purpose of this study was to study the effect of occupational exposure on respiratory health in wood pellet workers. Thirty-nine men working with wood pellet production at six plants were investigated with a questionnaire, medical examination, allergy screening, spirometry, and nasal peak expiratory flow (nasal PEF). Exposure to wood dust and monoterpenes was measured. The wood pellet workers reported a higher frequency of nasal symptoms, dry cough, and asthma medication compared to controls from the general population. There were no differences in nasal PEF between work and leisure time. A lower lung function than expected (vital capacity [VC], 95%; forced vital capacity in 1 second [FEV 1 ], 96% of predicted) was noted, but no changes were noted during shifts. There was no correlation between lung function and years working in pellet production. Personal measurements of wood dust at work showed high concentrations (0.16-19 mg/m 3 ), and exposure peaks when performing certain work tasks. Levels of monoterpenes were low (0.64-28 mg/m 3 ). There was no association between exposure and acute lung function effects. In this study of wood pellet workers, high levels of wood dust were observed, and that may have influenced the airways negatively as the study group reported upper airway symptoms and dry cough more frequently than expected. The wood pellet workers had both a lower VC and FEV 1 than expected. No cross-shift changes were found.

Co-gasification of pelletized wood residues

Energy Technology Data Exchange (ETDEWEB)

Carlos A. Alzate; Farid Chejne; Carlos F. Valdes; Arturo Berrio; Javier De La Cruz; Carlos A. Londono [Universidad Nacional de Colombia, Antioquia (Colombia). Grupo de Termodinamica Aplicada y Energias Alternativas

2009-03-15

A pelletization process was designed which produces cylindrical pellets 8 mm in length and 4 mm in diameter. These ones were manufactured using a blend of Pinus Patula and Cypress sawdust and coal in proportions of 0%, 5%, 10%, 20%, and 30% v/v of coal of rank sub-bituminous extracted from the Nech mine (Amaga-Antioquia). For this procedure, sodium carboxymethyl cellulose (CMC) was used as binder at three different concentrations. The co-gasification experiments were carried out with two kinds of mixtures, the first one was composed of granular coal and pellets of 100% wood and the second one was composed of pulverized wood and granular coal pellets. All samples were co-gasified with steam by using an electrical heated fluidized-bed reactor, operating in batches, at 850{sup o}C. The main components of the gaseous product were H{sub 2}, CO, CO{sub 2}, CH{sub 4}, and N{sub 2} with approximate quantities of 59%, 6.0%, 20%, 5.0%, and 9.0% v/v, respectively, and the higher heating values ranged from between 7.1 and 9.5 MJ/Nm{sup 3}.

GLOBAL WOOD PELLET INDUSTRY AND MARKET – CURRENT DEVELOPMENTS AND OUTLOOK

Energy Technology Data Exchange (ETDEWEB)

Thrän, Daniela; Peetz, David; Schaubach, Kay; Trømborg, Erik; Pellini, Alessandro; Lamers, Patrick; Hess, J. Richard; Schipfer, Fabian; Hektor, Bo; Olsson, Olle; Bruce, Lena; Stelte, Wolfgang; Proskurina, Svetlana; Heinimo, Jussi; Benedetti, Luca; Mai-Moulin, Thuy; Junginger, Martin; Craggs, Laura; Wild, Michael; Murray, Gordan; Diaz-Chavez, Rocio; Thiermann, Ute; Escobar, F. J.; Goldemberg, J.; Coelho, S. T.

2017-06-01

The wood pellet use in the heating and electricity sector has recorded a steady growth in the last years. IEA bioenergy task 40 carried out an update of the situation on the national pellet markets in the most relevant pellet producing countries and the global development as well. Various country specific data is collected and compiled for more than 30 countries, containing updated information about regulatory framework, production, consumption, price trends, quality standards and trade aspects. The analysis confirmed the positive development in terms of production and consumption of wood pellets in almost all countries. In 2015 more than 26 Mt of wood pellets have been produced and consumed worldwide. Technologies and markets become more mature. Increased international pellet trade needs to be supported by adequate frame condition not only for commerce, but also with regard to sustainability issues.

Lab and Bench-Scale Pelletization of Torrefied Wood Chips

DEFF Research Database (Denmark)

Shang, Lei; Nielsen, Niels Peter K.; Stelte, Wolfgang

2013-01-01

Combined torrefaction and pelletization is used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. In the present study, a single-pellet press tool was used to screen for the effects of pellet die temperature, moisture cont...... of the torrefied pellets was higher and the particle size distribution after grinding the pellets was more uniform compared to conventional wood pellets....

Wood pellets, what else? : Greenhouse gas parity times of European electricity from wood pellets produced in the south-eastern United States using different softwood feedstocks

NARCIS (Netherlands)

Hanssen, Steef V.; Duden, Anna S.; Junginger, Martin; Dale, Virginia H.; van der Hilst, Floortje

Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas (GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are

The economic potential of wood pellet production from alternative, low-value wood sources in the southeast of the US

NARCIS (Netherlands)

Hoefnagels, Ric; Junginger, Martin; Faaij, Andre

2014-01-01

The global demand for wood pellets used for energy purposes is growing. Therefore, increased amounts of wood pellets are produced from primary forestry products, such as pulp wood. The present analysis demonstrates that substantial amounts of alternative, low-value wood resources are available that

Wood pellets and work environment; Traepiller og arbejdsmiljoe

Energy Technology Data Exchange (ETDEWEB)

Skov, S.

2012-07-01

The project aim was to evaluate the working environment in the production, transport and use of wood pellets. Furthermore, obtained knowledge and guidelines should be disseminated to relevant audiences. The first aim was achieved by making dust measurements at various relevant locations and analyze the results. Several technical problems regarding the measurements occurred during the project. In general, the manual handling of pellets often is a short-term task, which limits the amount of dust that can be collected on the sampling filter. The solution to this problem could be the use of in situ monitoring equipment, however, this technic did not work well for wood dust. Dissemination is mainly done by publishing the findings and guidelines on the webpage www.fyrmedpiller.dk. The result shows that there are widespread dust problems associated with the use and handling of pellets. The result may have been expected in the wood pellet industry, which has been reluctant to support this project. Legislation on the working environment has set a threshold limit for the dust concentration in the air on max 1 mg of dust per cubic meters of air over a working day and in over shorter periods this limit may be doubled. These threshold values were exceeded in many cases. Brief overview: The production of pellets takes place in a very dusty working environment, but the specific pelletizing and bagging processes only produce limited amounts of dust. The dust problems are major in the large warehouses where the handling of the raw material for the pellets increases the dust concentration in the air to levels that by far exceeds the legal threshold values. The work is mainly carried out from the cabin of different machines e.g. loaders and bobcats. It turns out that the average dust concentration in these cabins with filters also exceeds the threshold values. The transports of wood pellets include loading, unloading and delivery of loose pellets, all situations that are critical

Transatlantic wood pellet trade demonstrates telecoupled benefits

Directory of Open Access Journals (Sweden)

Esther S. Parish

2018-03-01

Full Text Available European demand for renewable energy resources has led to rapidly increasing transatlantic exports of wood pellets from the southeastern United States (SE US since 2009. Disagreements have arisen over the global greenhouse gas reductions associated with replacing coal with wood, and groups on both sides of the Atlantic Ocean have raised concerns that increasing biomass exports might negatively affect SE US forests and the ecosystem services they provide. We use the telecoupling framework to test assertions that the intended benefits of the wood pellet trade for Europe might be offset by negative consequences in the SE US. Through a review of current literature and available data sets, we characterize the observed and potential changes in the environmental, social, and economic components of the sending and receiving regions to assess the overall sustainability of this renewable energy system. We conclude that the observed transatlantic wood pellet trade is an example of a mutually beneficial telecoupled system with the potential to provide environmental and socioeconomic benefits in both the SE US and Europe despite some negative effects on the coal industry. We recommend continued monitoring of this telecoupled system to quantify the environmental, social, and economic interactions and effects in the sending, receiving, and spillover systems over time so that evidence-based policy decisions can be made with regard to the sustainability of this renewable energy pathway.

Emissions from small scale combustion of pelletized wood fuels

International Nuclear Information System (INIS)

Bachs, A.

1998-01-01

Combustion of wood pellets in small scale heating systems with an effect below 20 kW has increased. During the winter season 1995/96 1500 small plants for heating houses are estimated to be in operation. Stack emissions from three pellet burners and two pellet stoves have been studied at laboratory. Different pellet qualities were tested. When the fraction of fines increased also the NO x emissions increased with about 10 %. As reference fuel 8 mm pellets was used. Tests with 6 mm pellets gave, in most cases, significant lower emissions of CO and THC. Eleven stoves, burners and boilers were studied in a field test. The results show that all the plants generally have higher emissions in the field than during conditions when the plants are adjusted with a stack gas monitoring instrument. A conclusion is that it is difficult for the operator to adjust the plant without a monitoring instrument. The emissions from the tested plants give an estimation of stack gas emissions from small scale pellet plants. The difference between the 'best' and 'worst' technologies is big. The span of emissions with the best technology to the worst is given below. The interval is concerning normal combustion . During abnormal conditions the emissions are on a significant higher level: * CO 80-1 000 mg/MJ; * Tar 0,3-19 mg/MJ; * THC (as methane equivalents) 2-100 mg/MJ; * NO x 50-70 mg/W;, and * Dust emissions 20-40 mg/MJ. Emissions from pellets heating are lower than from wood combustion and the best technology is close to the emission from oil burners. Wood and pellets have the same origin but the conditions to burn them in an environmental friendly way differ. Combustion of pellets could be improved through improved control of the air and fuel ratio that will create more stable conditions for the combustion

Occupational exposure of aldehydes resulting from the storage of wood pellets.

Science.gov (United States)

Rahman, Mohammad Arifur; Rossner, Alan; Hopke, Philip K

2017-06-01

An exposure assessment was conducted to investigate the potential for harmful concentrations of airborne short chain aldehydes emitted from recently stored wood pellets. Wood pellets can emit a number of airborne aldehydes include acetaldehyde, formaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and hexanal. Exposure limits have been set for these compounds since they can result in significant irritation of the upper respiratory system at elevated concentrations. Formaldehyde is a recognized human carcinogen and acetaldehyde is an animal carcinogen. Thus, air sampling was performed in a wood pellet warehouse at a pellet mill, two residential homes with bulk wood pellet storage bins, and in controlled laboratory experiments to evaluate the risk to occupants. Using NIOSH method 2539, sampling was conducted in five locations in the warehouse from April-June 2016 when it contained varying quantities of bagged pellets as well as two homes with ten ton bulk storage bins. The aldehyde concentrations were found to increase with the amount of stored pellets. Airborne concentrations of formaldehyde were as high as 0.45 ppm in the warehouse exceeding the NIOSH REL-C, and ACGIH TLV-C occupational exposure limits (OELs). The concentrations of aldehydes measured in the residential bins were also elevated indicating emissions may raise indoor air quality concerns for occupants. While individual exposures are of concern the combined irritant effect of all the aldehydes is a further raise the concerns for building occupants. To minimize exposure and the risk of adverse health effects to a building's occupants in storage areas with large quantities of pellets, adequate ventilation must be designed into storage areas.

Adopters and non-adopters of wood pellet heating in Norwegian households

International Nuclear Information System (INIS)

Sopha, Bertha Maya; Hertwich, Edgar G.; Kloeckner, Christian A.

2011-01-01

The aim of the present paper is to understand the differences between adopters and non-adopters of wood pellet heating in Norwegian households by comparing the two groups with regard to key points of adoption. A mail survey of 669 adopters and 291 non-adopters of wood pellet heating was conducted in 2008. Results indicate that there are significant differences between groups with respect to socio-demographic factors, decision-related factors, heating systems adopted and reasons for shifting heating systems. The results also indicate that the adopter group shows characteristics of early adopters, whereas the non-adopter group has characteristics of late adopters. The results for levels of income and education contradict what would be predicted from theory, however. Both groups show no significant difference with respect to values, but the perception of which heating system is the most environmentally friendly differs significantly. The top three reasons cited by the adopter group for installing wood pellet heating are getting an environmentally friendly heating system, low operation costs and an anticipated increase in electricity prices. According to the non-adopter group, the main barriers to adoption are high installation costs, followed by the difficulties of refitting the house for wood pellet heating. A higher subsidy (i.e., an average of 64% of the total installation cost) rather than the current subsidy of up to 20% was required by the non-adopter group to switch to wood pellet heating. (author)

Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

Directory of Open Access Journals (Sweden)

Horváth Jozef

2015-06-01

Full Text Available With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m−2 and 50 kW.m−2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

A model for establishing a win-win relationship between a wood pellets manufacturer and its customers

International Nuclear Information System (INIS)

Uran, Vedran

2010-01-01

This paper investigates the possibility of establishing a win-win relationship between a wood pellets manufacturer and its customers when the manufacturer possesses a power plant fueled by biomass and buys wood material from forest companies. Two prerequisites must be fulfilled for this relationship. First, the price of wood pellets should be lower than the fuel currently used by potential wood pellets customers and, second, the price of wood material as a raw material for producing the wood pellets should not jeopardize the profitability of the operations of the wood pellets manufacturer, who also produces electricity from biomass and sells it to the state at the feed-in tariff price. A mathematical model has been developed for each prerequisite and applied to several examples. The results demonstrate that a win-win relation can be established in Croatia and most of the Member States of the EU. (author)

Monitoring of carbon monoxide in residences with bulk wood pellet storage in the Northeast United States.

Science.gov (United States)

Rossner, Alan; Jordan, Carolyn E; Wake, Cameron; Soto-Garcia, Lydia

2017-10-01

The interest in biomass fuel is continuing to expand globally and in the northeastern United States as wood pellets are becoming a primary source of fuel for residential and small commercial systems. Wood pellets for boilers are often stored in basement storage rooms or large bag-type containers. Due to the enclosed nature of these storage areas, the atmosphere may exhibit increased levels of carbon monoxide. Serious accidents in Europe have been reported over the last decade in which high concentrations of carbon monoxide (CO) have been found in or near bulk pellet storage containers. The aim of this study was to characterize the CO concentrations in areas with indoor storage of bulk wood pellets. Data was obtained over approximately 7 months (December 2013 to June 2014) at 25 sites in New Hampshire and Massachusetts: 16 homes using wood pellet boilers with indoor pellet storage containers greater than or equal to 3 ton capacity; 4 homes with wood pellet heating systems with outdoor pellet storage; 4 homes using other heating fuels; and a university laboratory site. CO monitors were set up in homes to collect concentrations of CO in the immediate vicinity of wood pellet storage containers, and data were then compared to those of homes using fossil fuel systems. The homes monitored in this study provided a diverse set of housing stock spanning two and a half centuries of construction, with homes built from 1774 to 2013, representing a range of air exchange rates. The CO concentration data from each home was averaged hourly and then compared to a threshold of 9 ppm. While concentrations of CO were generally low for the homes studied, the need to properly design storage locations for pellets is and will remain a necessary component of wood pellet heating systems to minimize the risk of CO exposure. This paper is an assessment of carbon monoxide (CO) exposure from bulk wood pellet storage in homes in New Hampshire and Massachusetts. Understanding the CO concentrations

European wood pellet market integration - A study of the residential sector

International Nuclear Information System (INIS)

Olsson, Olle; Hillring, Bengt; Vinterbaeck, Johan

2011-01-01

The integration of European energy markets is a key goal of EU energy policy, and has also been the focal point of many scientific studies in recent years. International markets for coal, oil, natural gas and electricity have previously been investigated in order to determine the extent of the respective markets. This study enhances this field of research to bioenergy markets. Price series data and time series econometrics are used to determine whether residential sector wood pellet markets of Austria, Germany and Sweden are integrated. The results of the econometric tests show that the German and Austrian markets can be considered to be integrated, whereas the Swedish market is separate from the other two countries. Although increased internationalization of wood pellet markets is likely to contribute to European price convergence and market integration, this process is far from completed. (author)

Study on the optimization of the pellet production and on the development of a forest-wood-pellet chain

OpenAIRE

Sgarbossa, Andrea

2015-01-01

The biomass and biofuels markets have increased substantially in the last two decades, mainly driven by the national and European policy targets on green energy. The same positive trend is registered in particular for wood pellet markets. In comparison with other wooden biofuels (firewood or wood-chips) pellets have a number of positive aspects such as: - regular and optimized shape; - wide range of energetic applications (to produce thermal energy, syngas, electricity); - high so...

Status and prospects for renewable energy using wood pellets from the southeastern United States

DEFF Research Database (Denmark)

Dale, Virginia H.; Kline, Keith L.; Parish, Esther S.

2017-01-01

The ongoing debate about costs and benefits of wood-pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention...... as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, 'How is the production of wood pellets in the SE USA affecting forest systems and the ecosystem...... services they provide?' To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide...

Production of wood pellets. Influence of additives on production, quality, storage, combustion and life cycle analysis of wood pellets; Herstellung von Holzpellets. Einfluss von Presshilfsmitteln auf Produktion, Qualitaet, Lagerung, Verbrennung sowie Energie- und Oekobilanz von Holzpellets

Energy Technology Data Exchange (ETDEWEB)

Hasler, P.; Nussbaumer, T. [Verenum, Zuerich (Switzerland); Buerli, J. [Buerli Pellets, Willisau (Switzerland)

2001-07-01

This report for the Swiss Federal Office of Energy (SFOE) presents the results of a study concerning the influence of additives on the various factors related to the manufacture of wood pellets and their use. Results of tests concerning the production, storage and combustion of wood pellets with and without additives are presented. Process modifications are discussed. The report shows that for all investigated additives neither energy consumption nor pellet throughput was improved. The influence of additives on the mechanical strength of the pellets is discussed, as are the combustion characteristics of the pellets, which emit significantly lower levels of NO{sub x} and particulate matter than typical wood chips. The authors recommend the application of advanced control technology to ensure optimum combustion conditions. A life-cycle analysis is presented which shows that pellets are ecologically more favourable than wood chips. The ecological potential for improvement in the manufacturing process is discussed, including emission reductions and heat recovery.

Psychological factors in the diffusion of sustainable technology: a study of Norwegian households' adoption of wood pellet heating

Energy Technology Data Exchange (ETDEWEB)

Sopha, Bertha Maya; Kloeckner, Christian A.

2010-07-01

Full text: This paper aims to understand the determinants of the adoption of wood pellet technology for home heating to identify possible strategies towards the slow diffusion of wood pellet in Norway. A mail survey of 737 Norwegian households was conducted in 2008, involving wood pellet adopters and non wood pellet adopters as respondents. An integrated model combining psychological factors (such as intentions, attitudes, perceived behavioral control, habits and norms), perceived wood pellet heating characteristics, and ecological and basic values is applied to predict the installation of a wood pellet stove retrospectively. Results from a path analysis gain empirical support for the proposed integrated model. Wood pellet heating adoption is mainly predicted by a deliberate decision process starting with the evaluation of heating system characteristics, mediated by attitudes and intentions. Perceived behavioural control and habits pose relevant barriers to the adoption process. The influence of norms and values are indirect and only minor in the given market conditions. The most important heating system characteristics in the analysis were perceived functional reliability and perceived installation and maintenance costs. Possible intervention strategies to speed up wood pellet adoption in Norway are discussed in the last part of the paper. (Author)

Modeling the impacts of wood pellet demand on forest dynamics in southeastern United States

NARCIS (Netherlands)

Duden, Anna S.; Verweij, Pita A.; Junginger, H. Martin; Abt, Robert C.; Henderson, Jesse D.; Dale, Virginia H.; Kline, Keith L.; Karssenberg, Derek; Verstegen, Judith A.; Faaij, André P.C.; van der Hilst, Floor

2017-01-01

The export of wood pellets from the southeastern United States (USA) has grown significantly in recent years, following rising demand from Europe. Increased wood pellet demand could lead to spatially variable changes in timberland management and area in the USA. This study presents an assessment of

Wood pellet milling tests in a suspension-fired power plant

DEFF Research Database (Denmark)

Masche, Marvin; Puig-Arnavat, Maria; Wadenbäck, Johan

2018-01-01

classification (i.e., the classifier cut size) are affected by the internal pellet particle size distribution obtained after pellet disintegration in hot water. Furthermore, optimal conditions for comminuting pellets were identified. The milling behavior was assessed by determining the specific grinding energy...... consumption and the differential mill pressure. The size and shape of comminuted pellets sampled from burner pipes were analyzed by dynamic image analysis and sieve analysis, respectively. The results showed that the internal pellet particle size distribution affected both the milling behavior...... similar. Mill operating changes had a negligible effect on the original elongated wood particle shape. To achieve the desired comminuted product fineness (i.e., the classifier cut size) with lower specific grinding energy consumption, power plant operators need to choose pellets with a finer internal...

Impact of wood pellets export on the development of their production in Serbia with the effects of substituting enegry from fossil fuels and reduction of carbon dioxide emission

Directory of Open Access Journals (Sweden)

Glavonjić Branko

2016-01-01

Full Text Available The paper presents the results of researching the impact of export on the production of wood pellets as well as the situation on the market for this wood fuel in Serbia. Objective of the research was to produce scientifically and professionally founded conclusions and the related adequate recommendations to the decision makers in order to improve the situation on wood pellets market in Serbia and eliminate the existing problems which significantly burden and slow down this development. Special objective of the research was to observe the contributions of wood pellets to the mitigation of climate changes using Serbia as the example. Results of the conducted research show that the expansion of the consumption (demand increase in the European Union countries in the last fifteen years and the related increase of export from Serbia are the most significant factors which have influenced the development of wood pellets production in Serbia. Parameters of econometric model of the impact of export on the increase of production show that production increase of 1.17% can be expected with the increase of export of 1%. Thus, the number of wood pellet producers has rapidly increased in the last ten years, from 2 producers in 2006 to 52 active producers in 2016. Increase of the number of producers was also accompanied by the increase of the installed capacities. At the end of 2015, total installed capacities for wood pellet production in Serbia reached 550 thousand tons, and the realized production was 229 thousand tons, or 41.6% of the installed capacity. Consumption of wood pellets in Serbia in the last four years achieved significant increase and reached the level of 89 thousand tons in 2015. However, concerning the segment of wood pellets consumption in Serbia, the situation is still unsatisfactory despite the fact that the consumption has been increasing year after year. Average price of 1 kWh of energy from wood pellets exported from Serbia was in the

Norwegian households' perception of wood pellet stove compared to air-to-air heat pump and electric heating

International Nuclear Information System (INIS)

Sopha, Bertha Maya; Kloeckner, Christian A.; Skjevrak, Geir; Hertwich, Edgar G.

2010-01-01

In 2003, the high dependency on electric heating combined with the high electricity price prompted a significant number of Norwegian households to consider alternative heating systems. The government introduced economic support for wood pellet heating and heat pumps. In contrast to the fast growing heat pump market, this financial support has not resulted in a widespread adoption of wood pellet heating. This paper studies factors that influence the choice of heating system based on Norwegian households' perceptions. Electric heating, heat pump and wood pellet heating were compared, with a special focus on wood pellet heating. This study was conducted as a questionnaire survey on two independent samples. The first sample consisted of 188 randomly chosen Norwegian households, mainly using electric heating; the second sample consisted of 461 households using wood pellet heating. Our results show that socio-demographic factors, communication among households, the perceived importance of heating system attributes, and the applied decision strategy all influence the Norwegian homeowners. The significance of these factors differs between the two samples and the preferred type of anticipated future heating system. Strategies for possible interventions and policy initiatives are discussed.

Raw materials for pellets; Rohstoffe fuer Pellets

Energy Technology Data Exchange (ETDEWEB)

Neumann, H.

2008-01-15

In order to keep the pellet prices stable, producers look for new raw materials. Sawdust as a former basis also competes with the manufacturers of chip boards and paper. Three classes of quality are discussed by the pellet manufacturers: (a) the DINplus pellet as a premium segment for which high-quality sawdust are used; (b) a wood pellet from natural wood with varying quality for the utilization in larger plants with filters; (c) the inexpensive industrial wood pellet which deviates from the DINplus commodity regarding to the ingredients and form and could be fired in larger power stations.

Wood pellet production costs under Austrian and in comparison to Swedish framework conditions

NARCIS (Netherlands)

Obernberger, I.; Thek, G.

2004-01-01

Owing to the rapidly increasing importance of pellets as high-quality biomass fuel in Austria and Europe within the last years, many companies, mainly from the wood industry, are thinking of entering this market. The calculation of the production costs before starting a pellet plant is essential for

The international logistics of wood pellets for heating and power production in Europe: Costs, energy-input and greenhouse gas balances of pellet consumption in Italy, Sweden and the Netherlands

NARCIS (Netherlands)

Sikkema, R.|info:eu-repo/dai/nl/110609913; Junginger, H.M.|info:eu-repo/dai/nl/202130703; Pichler, W.; Hayes, S.; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X

2010-01-01

The European wood pellet market is booming: concerns about climate change and renewable energy targets are predominant drivers. The aim of this analysis is to compare typical wood pellet chains from the purchase of the feedstock from sawmills to the conversion into heat or electricity. Cost

The effect of control parameters to the quality of small-scale wood pellet combustion

Energy Technology Data Exchange (ETDEWEB)

Ruusunen, M. (Oulu Univ. (Finland). Contol Engineering Lab.), Email: mika.ruusunen@oulu.fi; Korpela, T.; Bjoerkqvist, T. (Tampere Univ. of Technology (Finland). Dept. of Automation Science and Engineering), Email: timo.korpela@tut.fi, Email: tomas.bjorqvist@tut.fi

2009-07-01

The target is to clear out control variables and requirements for clean small-scale wood pellet combustion (<100 kW{sub th}). Experimental runs were carried out in the form of design of experiments (DOE) with two commercial 15 kW pellet burners, namely a horizontal gas-burner and a conventional horizontal burner in a 20 kW commercial pellet boiler. Analysed variables were fuel power, draught, air flows, and fuel feed period, and research variables were CO, O{sub 2} and efficiency. The target was to identify and characterise separately the magnitude and direction of the effect of each factor. After process identification and variable optimisation, the results show strong influence of the studied control parameters on the efficiency and the emissions. The effects and interactions between different process variables were rather similar with both burners. The major effects for CO levels were fuel feed and additionally draught affected in case of wood gas combustion. Additionally, the effects on combustion efficiency is described by draught, air feed and fuel feed period. Furthermore, the fuel feed period affected the excess air level in case of direct combustion principle. It was noticed, however, that the combustion properties and optimal parameter values vary significantly between the two cases. (orig.)

A life-cycle comparison of the energy, environmental and economic impacts of coal versus wood pellets for generating heat in China

International Nuclear Information System (INIS)

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

2017-01-01

In this study, we investigated whether wood pellets were more sustainable than coal for heating buildings in China by presenting a “fuel-to-heat” energy, environmental and economic comparison for both energy sources. Pellet and coal heating systems were modeled using a process-based life cycle inventory modeling approach, and the energy consumption and air pollutant emissions were calculated in Gigajoules (GJ). Wood pellets were also analyzed for their costs and market competitiveness against coal and other fossil fuel heating alternatives. The results showed that the energy saving potential from using pellets instead of coal was 1382 MJ for every 1-GJ of heat generated. Greenhouse gas emissions from pellets were 11.76 kg CO_2-eq GJ"−"1 heat, which were approximately 94% less than emissions from coal heating systems. Also, the wood pellet systems reduced SO_2, NO_x and PM emissions by 86%, 56% and 33%. However, the cost of pellets is significantly higher than the cost for coal, and is the primary impediment for the transition from coal to pellets in China. In addition, multiple consumers of wood residue, unstable heat values of pellet, limited supplies, and the lack of product and heating equipment standards also render the transition from coal to pellets impractical. - Highlights: • Process-based LCI modeling method was used for fuel-to-heat environmental assessment. • A coal-to-pellet shift for heat generation enables notable environmental benefits. • An average subsidy of 5.80 $ is needed for 1-GJ heat generation from the PTH system. • Low coal price and high feedstock cost hinder the wood pellet industry's development.

LIBS detection of heavy metal elements in liquid solutions by using wood pellet as sample matrix

International Nuclear Information System (INIS)

Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong

2013-01-01

Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of heavy metals in liquid sample. A new approach was presented to improve the detection limit and minimize the sample matrix effects, in which dried wood pellets absorbed the given amounts of Cr standard solutions and then were baked because they have stronger and rapid absorption properties for liquid samples as well as simple elemental compositions. In this work, we have taken a typical heavy metal Cr element as an example, and investigated the spectral feasibility of Cr solutions and dried wood pellets before and after absorbing Cr solutions at the same experimental conditions, respectively. The results were demonstrated to successfully produce a superior analytical response for heavy metal elements by using wood pellet as sample matrix according to obtained LOD of 0.07 ppm for Cr element in solutions. (author)

LIBS Detection of Heavy Metal Elements in Liquid Solutions by Using Wood Pellet as Sample Matrix

International Nuclear Information System (INIS)

Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong

2014-01-01

Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of heavy metals in liquid samples. A new approach was presented to lower the limit of detection (LOD) and minimize the sample matrix effects, in which dried wood pellets absorbed the given amounts of Cr standard solutions and then were baked because they have stronger and rapid absorption properties for liquid samples as well as simple elemental compositions. In this work, we have taken a typical heavy metal Cr element as an example, and investigated the spectral feasibility of Cr solutions and dried wood pellets before and after absorbing Cr solutions at the same experimental conditions. The results were demonstrated to successfully produce a superior analytical response for heavy metal elements by using wood pellet as sample matrix according to the obtained LOD of 0.07 ppm for Cr element in solutions

Assessing the representativeness of durability tests for wood pellets by DEM Simulation - Comparing conditions in a durability test with transfer chutes

Science.gov (United States)

Mahajan, Aditya; Dafnomilis, Ioannis; Hancock, Victoria; Lodewijks, Gabriel; Schott, Dingena

2017-06-01

Dust generation when handling wood pellets is related to the durability of the product, in other words the wear rate of particles subject to forces. During transport, storage and handling wood pellets undergo different forces when interacting with different pieces of equipment. This paper assesses the representativeness of the tumbling can test in relation to transfer chutes, by comparing forces acting on wood pellets in durability tests and in transfer chutes using DEM. The study also incorporates effects such as shape and size variations. The results showed that the tumbling can test underestimates compressive and tangential forces. Since the tested material is subject to milder conditions than in reality, it can be concluded that this test is not representative for the conditions in the supply chain of wood pellets.

Impact of fuel quality and burner capacity on the performance of wood pellet stove

OpenAIRE

Petrović-Bećirović Sanja B.; Manić Nebojša G.; Stojiljković Dragoslava D.

2015-01-01

Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8 and 10 kW), used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results o...

Pell-Sim - dynamic model for forecasting storage and distribution of wood pellets

International Nuclear Information System (INIS)

Vinterbaeck, Johan

2004-01-01

This study examined the system of wood pellet distribution to residential consumers. The distribution cost for a residential pellet consumer typically represents 30% of the per tonne price and of this share, the inventory cost could be more than 50%. Important administrative activities in physical distribution are forecasting demand and inventory control. One way to improve distribution systems would be to optimise inventory management for pellet distributors. The aim of this study was to propose improvements in pellet distribution management by using tools from systems analysis. The ultimate goal was to present an optimised storage level curve adapted to the mid-Swedish community of Avesta. An internal model for optimising inventory management, Pell-Sim, was constructed, composed of two integrated parts: a simulation unit to forecast residential wood pellet demand and a spreadsheet unit with inventory-related functions. Daily outdoor temperatures basically regulated the simulation unit. An order point system was chosen for reordering. The residential customers of a distribution company were divided into two groups, delivery and collecting customers, which were statistically treated separately. When collecting and delivery customer input inventories were normally distributed in the intervals from 0 to 3500 kg and 6500 kg, respectively, their annual means of total delivery were both about 7000 kg/customer, which was the desired and empirical level. The expected pellet customer orders were negatively correlated to mean daily temperatures, lagging behind about 1 month. Sensitivity analyses showed that monthly results for ordered quantity and total cost were particularly sensitive to ordering and carrying costs. The Pell-Sim programme can easily be adapted for distributors in other geographical regions. (Author)

Pell-Sim - dynamic model for forecasting storage and distribution of wood pellets

Energy Technology Data Exchange (ETDEWEB)

Vinterbaeck, Johan [Swedish Univ. of Agricultural Sciences, Dept. of Forest Management and Products, Uppsala (Sweden)

2004-12-01

This study examined the system of wood pellet distribution to residential consumers. The distribution cost for a residential pellet consumer typically represents 30% of the per tonne price and of this share, the inventory cost could be more than 50%. Important administrative activities in physical distribution are forecasting demand and inventory control. One way to improve distribution systems would be to optimise inventory management for pellet distributors. The aim of this study was to propose improvements in pellet distribution management by using tools from systems analysis. The ultimate goal was to present an optimised storage level curve adapted to the mid-Swedish community of Avesta. An internal model for optimising inventory management, Pell-Sim, was constructed, composed of two integrated parts: a simulation unit to forecast residential wood pellet demand and a spreadsheet unit with inventory-related functions. Daily outdoor temperatures basically regulated the simulation unit. An order point system was chosen for reordering. The residential customers of a distribution company were divided into two groups, delivery and collecting customers, which were statistically treated separately. When collecting and delivery customer input inventories were normally distributed in the intervals from 0 to 3500 kg and 6500 kg, respectively, their annual means of total delivery were both about 7000 kg/customer, which was the desired and empirical level. The expected pellet customer orders were negatively correlated to mean daily temperatures, lagging behind about 1 month. Sensitivity analyses showed that monthly results for ordered quantity and total cost were particularly sensitive to ordering and carrying costs. The Pell-Sim programme can easily be adapted for distributors in other geographical regions. (Author)

Combined heat and power unit using renewable raw materials. A cogeneration power plant with wood chips and pellets; BHKW auf Basis nachwachsender Rohstoffe. KWK mit Holzhackschnitzeln und Pellets

Energy Technology Data Exchange (ETDEWEB)

Lennartz, Marc Wilhelm

2013-07-15

The combined heat and power units of the next generation operate with renewable resources. The plants working with wood chips or pellets now are ready for mass production. So, farmers and foresters, trade and municipalities may pile in the decentralized, energetic self-sufficiency. Two companies have developed procedures with which combined heat and power plants based can be operated on wood chips or pellets.

Analytical inventory of process variables for sustainable development of a small business for integrated production of wood pellets

Directory of Open Access Journals (Sweden)

Merticaru Vasile

2017-01-01

Full Text Available The paper presents some theoretical considerations and the related deliverable results obtained within a research approach developed for analytically inventorying the process variables for a wood pellets micro-production activity integrated with self-providing crops of energetic willow. The study is part of a larger research approach intended to accurately define the appropriate specifications for developing a sustainable small business in this area. Within the particular research approach being discussed in the paper, some conceptual models have been structured and are proposed, based on process systematic analysis, as following: a model of the research general hypotheses; a model of the general conceptual research frame; a process flow model for the considered integrated processes, respectively wood pellets micro-production and energetic willow crops; a model for sustainability groups of indicators to be considered; two models for process variables inventorying and classification, one for each of the two considered integrated processes. After the research hypotheses are simplified by considering some particular implementing conditions, a final model of the investigated variables is submitted to discussion. Some adequate conclusions revealed by the research approach, together with some directions of further research development are finally identified and presented in the paper.

Report on the survey of the commercialization of wood biomass energy. Project on the production of wood pellet fuel; 2001 nendo mokushitsu baiomasu energy jigyoka chosa hokokusho. Mokushitsu peretto nenryo seizo jigyo

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-02-01

For the purpose of regenerating forestry and contributing to the policy for prevention of global warming, a potential study was made of the commercialization of the wood pellet using low-quality wood materials such as thinnings and wood pieces from lumber mill. In the study, based on the survey of raw materials of wood pellet and the demand amount, the scale of pellet production was assumed, and subjects were arranged toward the basic design of plant, evaluation of economical efficiency and commercialization. As a result of the study, the following subjects were extracted. In the study, the supply of lumbers of 2,800 t/y and securing of demand of about 1,600 t/y were set forth as a premise, but the subject was to secure the initial demand. The pellet combustor was higher in price than the kerosene combustor, and for the imported combustion equipment, the combustion of white pellet was supposed. It is necessary to develop combustor of pellets including the bark. In the trial calculation of the unit price of heat utilization (yen/Mcal), the pellet stove was about 3.3 times as high in price as the kerosene stove. It is necessary to reduce the pellet price down to 30 yen/kg or so by decreasing the cost of pellet production. (NEDO)

Solar heating, wood chips and pellets at Harpsund. An evaluation; Solvaerme, flis och pellets paa Harpsund. Utvaerdering

Energy Technology Data Exchange (ETDEWEB)

Nilsson, Leif; Perers, Bengt

2006-06-15

Harpsund is well-known for being the representation residence for the Swedish prime minister. Besides this function, it is also a production unit for milk and meat, with a livestock of about 500 animals. At Harpsund, a new production plant for heating and domestic hot water with a new distribution net was built by the Swedish authorities. Wood chips from the forests belonging to the estate are used for the heat production, together with wood pellets and solar heat. The old heating system was based on a technique with local production in each building and was in need of modernization. The new plant has been designed very attractively - great care has been taken to make it fit into the atmosphere of the surroundings. The solar collectors are placed on the roof of a garage for farming machines. The heat central contains three burners: one for wood chips with thermal power 250 kW, one 400 kW burner for pellets and one small 25 kW burner for pellets. The smallest unit is intended to support the solar system during the summer season. From the garage with the 327 m{sup 2} Aquasol Big AR solar collectors the solar heated glycol/ water is transported to the heat central in a culvert. The distance is 150 m. At the heat central, there is also a heat accumulator with a volume of 40 m{sup 3} of water. This is used both for the burners and for the solar heat. The monitoring and analysis of the plant show that it has good reliability and it is evident that the production capacity is adequate for all conceivable climate conditions. During one year of monitoring, the heat central produced 1,494 MWh of which 86 % came from wood chips, 9 % from pellets and 5 % from solar heat. It is unfavourable that the solar heat has to work against the return temperature of the heat distribution system. Also, the collector area seems to be somewhat too large for the demand for domestic hot water. The result for the specific investment for solar heat is therefore high: 13.21 SEK/kWh,year. It might

Online analysis of wood pellets. Quality parameters by near infrared spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Petersen Julius, Lars; Joergensen, Pia [Dong Energy Power, Fredericia (Denmark); Plejdrup Houmoeller, Lars [Arla Foods amba, Global Ingedients R and D, Videbaek (Denmark); Groenkaer Pedersen, Joan [Academy Engineer Chemistry Fertin Pharma, Vejle (Denmark); Anov, Dan

2010-07-01

A near infrared spectroscopy system was installed online in a wood pellet production facility. The objective was to translate real time spectra to useful chemical information, like calorific value, water- and ash content. It was possible to successfully determine water content and calorific value, whereas ash content proved troublesome. (orig.)

Fatal Accidents During Marine Transport of Wood Pellets Due to Off-gassing – Experiences from Denmark

DEFF Research Database (Denmark)

Hedlund, Frank Huess; Jarleivson Hilduberg, Øssur

2016-01-01

The atmosphere in unventilated wood pellet storage confinements, such as the cargo hold of marine vessels transporting pellets in solid bulk, can be severely oxygen deficient and contain deadly concentrations of harmful gasses, of which the most feared is the poisonous and odour-less carbon monox...

Pellets direct from the forest

International Nuclear Information System (INIS)

Keel, A.

2006-01-01

This article takes a look at developments in the market for wood pellets and their production from forest wood. The general situation in the booming pellets market is reviewed and the potential of this climate-neutral form of heating is discussed. Figures and prognoses on the use of wood pellets are presented. In particular, the potential for the use of forestry wood supplies to augment the use of wood wastes and sawdust from sawmills is looked at

Full-scale Milling Tests of Wood Pellets for Combustion in a Suspension-Fired Power Plant Boiler

DEFF Research Database (Denmark)

Masche, Marvin; Puig Arnavat, Maria; Wadenbäck, Johan

The size reduction of pelletized wood is crucial in suspension-fired power plants, and hence its milling characteristics are of interest to optimize the milling and combustion process. The objective of the study was to compare the size and shape of pellets disintegrated in hot water with that from......), and analyzing the comminuted particle shape and particle size distribution (PSD). Large-scale pellet comminution produced finer and wider PSDs than pellet disintegration in hot water, but only slightly altered the particle shape. The mill pressure loss, absorbed mill power, and hence SGEC depended on the pellet...

A Review of the Wood Pellet Value Chain, Modern Value/Supply Chain Management Approaches, and Value/Supply Chain Models

Directory of Open Access Journals (Sweden)

Natalie M. Hughes

2014-01-01

Full Text Available We reviewed 153 peer-reviewed sources to provide identification of modern supply chain management techniques and exploration of supply chain modeling, to offer decision support to managers. Ultimately, the review is intended to assist member-companies of supply chains, mainly producers, improve their current management approaches, by directing them to studies that may be suitable for direct application to their supply chains and value chains for improved efficiency and profitability. We found that information on supply chain management and modeling techniques in general is available. However, few Canadian-based published studies exist regarding a demand-driven modeling approach to value/supply chain management for wood pellet production. Only three papers were found specifically on wood pellet value chain analysis. We propose that more studies should be carried out on the value chain of wood pellet manufacturing, as well as demand-driven management and modeling approaches with improved demand forecasting methods.

Integration of a wood pellet burner and a Stirling engine to produce residential heat and power

International Nuclear Information System (INIS)

Cardozo, Evelyn; Erlich, Catharina; Malmquist, Anders; Alejo, Lucio

2014-01-01

The integration a Stirling engine with a pellet burner is a promising alternative to produce heat and power for residential use. In this context, this study is focused on the experimental evaluation of the integration of a 20 kW th wood pellet burner and a 1 kW e Stirling engine. The thermal power not absorbed by the engine is used to produce hot water. The evaluation highlights the effects of pellet type, combustion chamber length and cycling operation on the Stirling engine temperatures and thermal power absorbed. The results show that the position of the Stirling engine is highly relevant in order to utilize as much as possible of the radiative heat from the burner. Within this study, only a 5 cm distance change between the Stirling engine and the pellet burner could result in an increase of almost 100 °C in the hot side of the engine. However, at a larger distance, the temperature of the hot side is almost unchanged suggesting dominating convective heat transfer from the hot flue gas. Ash accumulation decreases the temperature of the hot side of the engine after some cycles of operation when a commercial pellet burner is integrated. The temperature ratio, which is the relation between the minimum and maximum temperatures of the engine, decreases when using Ø8 mm wood pellets in comparison to Ø6 mm pellets due to higher measured temperatures on the hot side of the engine. Therefore, the amount of heat supplied to the engine is increased for Ø8 mm wood pellets. The effectiveness of the engine regenerator is increased at higher pressures. The relation between temperature of the hot side end and thermal power absorbed by the Stirling engine is nearly linear between 500 °C and 660 °C. Higher pressure inside the Stirling engine has a positive effect on the thermal power output. Both the chemical and thermal losses increase somewhat when integrating a Stirling engine in comparison to a stand-alone boiler for only heat production. The overall efficiency

Assessment of pelletized biofuels

International Nuclear Information System (INIS)

Samson, R.; Duxbury, P.; Drisdelle, M.; Lapointe, C.

2000-04-01

There has been an increased interest in the development of economical and convenient renewable energy fuels, resulting from concerns about climate change and rising oil prices. An opportunity to use agricultural land as a means of producing renewable fuels in large quantities, relying on wood and agricultural residues only has come up with recent advances in biomass feedstock development and conversion technologies. Increasing carbon storage in the landscape and displacing fossil fuels in combustion applications can be accomplished by using switchgrass and short rotation willow which abate greenhouse gas emissions. The potential of switchgrass and short rotation willow, as well as other biomass residues as new feedstocks for the pellet industry is studied in this document. Higher throughput rates are facilitated by using switchgrass, which shows potential as a pelleting feedstock. In addition, crop drying requires less energy than wood. By taking into consideration energy for switchgrass production, transportation to the conversion facility, preprocessing, pelleting, and marketing, the overall energy balance of switchgrass is 14.5:1. Research on alfalfa pelleting can be applied to switchgrass, as both exhibit a similar behaviour. The length of chop, the application of high temperature steam and the use of a die with a suitable length/diameter ratio are all factors that contribute to the successful pelleting of switchgrass. Switchgrass has a similar combustion efficiency (82 to 84 per cent) to wood (84 to 86 per cent), as determined by combustion trials conducted by the Canada Centre for Mineral and Energy Technology (CANMET) in the Dell-Point close coupled gasifier. The energy content is 96 per cent of the energy of wood pellets on a per tonne basis. Clinker formation was observed, which necessitated some adjustments of the cleaner grate settings. While stimulating rural development and export market opportunities, the high yielding closed loop biofuels show

Small scale wood combustion in Germany. Recent research and trends

Energy Technology Data Exchange (ETDEWEB)

Maier, H.; Unterberger, S.; Hein, K.R.G. [Institute of Process Engineering and Power Plant Technology, University of Stuttgart (Germany)

1998-12-31

To reduce Europe`s greenhouse gas emission CO{sub 2} it is a challenging task utilising biomass fuels as there are wood or wood residues from the forest industry. The utilisation can be done either in commercially operated medium (> 50 kWth) or full scale (> 1 MWth) decentralised heat and power stations or in small scale (< 50 kWth) domestic heating systems. In small scale heating systems untreated wood logs, wood briquette or wood pellets and in few cases wood chips are used. The present market in Germany is focused on the use of wood logs. Presently, the use of wood pellets in small scale automatically operated boilers < 15 kW especially for low energy houses is discussed more and more. Since 1980 the installation of new wood fired small scale domestic heating systems reached a significant size due to the interest of the customers to have a alternative inhouse heating system and to increase the living comfort. In 1994 the amount of sold small scale heaters in Germany were in total about 133.258 units. The thermal power of in 1994 sold units is estimated of about 1350 MW which is a significant size in total with regard to domestic heating purposes. Since few years there is a clear market trend in Germany towards the installation of open fire stoves. Due to this trend in Germany and the design characteristic of open fire stoves using huge glass doors of glass windows it is very difficult to achieve a further reduction of emissions like CO and unburned volatile hydrocarbons (VOC). In the text the requirements for modern small scale wood fired stoves in Germany as well as the actual stage and trend of research and development (R and D) are discussed 4 refs.

Effect of raw material particle-size distribution on combustion characteristics of stem wood pellets; Paaverkan av partikelfraktionsfoerdelningen paa utbraenningshastigheten hos traepellets vid nyttjande av olika soenderdelningsmetoder

Energy Technology Data Exchange (ETDEWEB)

Israelsson, Samuel; Henriksson, Gunnar; Boman, Christoffer; Oehman, Marcus

2007-01-15

The objective of the project was to determine the effect of raw material particle-size distribution on combustion characteristics of stem wood pellets. Several well defined pellet qualities were produced from raw materials (stem wood of pine and spruce) which had both different particle-size distributions and were produced with different milling equipments (hammer mill/refiner). The pellets were produced in a traditional (bench-scale) pellet mill and in a laboratory pellet mill/press. The combustion characteristics of the individual pellets were determined in a laboratory scale oven. Char yield, -shrinkage, -density and the micro pore volume of the produced char were also determined. Differences in total conversion times of approximately 5 % at experimental condition relevant for typical pellets equipment were determined for the different pellet qualities. The underlying reasons for the obtained differences in the combustion characteristics between the different pellet qualities are discussed in the report

U.S. Forest Greenhouse Gas Impacts of a continued Expansion of E.U. Wood Pellet Demand

Science.gov (United States)

Latta, G.; Baker, J.; Ohrel, S. B.

2016-12-01

The United States has ambitious goals of greenhouse gas (GHG) reductions. A portion of these reductions are based on expected contributions from land use, land use change, and forestry (LULUCF). The European Union has similar goals which have resulted in a doubling of wood pellets exported from US ports destined for EU power plants over the last few years. There are potential conflicts between the GHG consequences of this pellet supply and the LULUCF contribution to US GHG goals. This study seeks to inform the discussion by modeling US forest GHG accounts using data measured on a grid of over 150,000 USDA Forest Service, Forest Inventory and Analysis (FIA) forestland plots across the conterminous United States. Empirical yield functions are estimate from plot log volume, biomass and carbon and provide the basis for changes in forest characteristics over time. Demand data based on a spatial database of over 2,000 forest product manufacturing facilities representing 11 intermediate and 13 final solid and pulpwood products. Manufacturing and logging costs are specific to slope, log size, and volume removed along with transportation costs based on fuel prices, FIA plot, and milling locations. The resulting partial spatial equilibrium model of the US forest sector is solved annually for the period 2010 - 2030 with demand shifted by energy prices and macroeconomic indicators from the US EIA's Annual Energy Outlook for a series of potential wood pellet export targets. For each wood pellet export level simulated, figures showing historic and scenario-specific forest products production are generated. Maps of the spatial allocation of both forest harvesting and carbon fluxes are presented at the National level and detail is given in both the US North and Southeast.

Downdraft gasification of pellets made of wood, palm-oil residues respective bagasse: Experimental study

International Nuclear Information System (INIS)

Erlich, Catharina; Fransson, Torsten H.

2011-01-01

The downdraft gasification technology has an increased interest among researchers worldwide due to the possibility to produce mechanical and electrical power from biomass in small-scale to an affordable price. The research is generally focused on improvement of the performance and optimizing of a certain gasifier, on testing different fuels, on increasing the user-friendliness of the gasifier and on finding other uses for the product gas than in an IC-engine, for example liquid fuel production. The main objective with the gasification tests presented here is to further contribute in the field by studying the impact of the char bed properties such as char bed porosity and pressure drop on the gasification performance as well as the impact of fuel particle size and composition on the gasification process in one and the same gasifier. In addition, there is very little gasification data available in literature of 'before disregarded' fuels such as sugar cane bagasse from sugar/alcohol production and empty fruit bunch (EFB) from the palm-oil production. By pelletizing these residues, it is possible to introduce them into downdraft gasification technology which has been done in this study. The results show that one and the same reactor can be used for a variety of fuels in pellet form, but at varying air-fuel ratios, temperature levels, gas compositions and lower heating values. Gasification of wood pellets results in a richer producer gas while EFB pellets give a poorer one with higher contents of non-combustible compounds. In this gasification study, there is almost linear relation between the air-fuel ratio and the cold-gas efficiency for the studied fuels: Higher air-fuel ratios result in better efficiency. The pressure drop in the char bed is higher for more reactive fuels, which in turn is caused by low porosity char beds.

How the user can influence particulate emissions from residential wood and pellet stoves: Emission factors for different fuels and burning conditions

Science.gov (United States)

Fachinger, Friederike; Drewnick, Frank; Gieré, Reto; Borrmann, Stephan

2017-06-01

For a common household wood stove and a pellet stove we investigated the dependence of emission factors for various gaseous and particulate pollutants on burning phase, burning condition, and fuel. Ideal and non-ideal burning conditions (dried wood, under- and overload, small logs, logs with bark, excess air) were used. We tested 11 hardwood species (apple, ash, bangkirai, birch, beech, cherry, hickory, oak, olive, plum, sugar maple), 4 softwood species (Douglas fir, pine, spruce, spruce/fir), treated softwood, beech and oak wood briquettes, paper briquettes, brown coal, wood chips, and herbaceous species (miscanthus, Chinese silver grass) as fuel. Particle composition (black carbon, non-refractory, and some semi-refractory species) was measured continuously. Repeatability was shown to be better for the pellet stove than for the wood stove. It was shown that the user has a strong influence on wood stove emission behavior both by selection of the fuel and of the burning conditions: Combustion efficiency was found to be low at both very low and very high burn rates, and influenced particle properties such as particle number, mass, and organic content in a complex way. No marked differences were found for the emissions from different wood species. For non-woody fuels, much higher emission factors could be observed (up to five-fold increase). Strongest enhancement of emission factors was found for burning of small or dried logs (up to six-fold), and usage of excess air (two- to three-fold). Real world pellet stove emissions can be expected to be much closer to laboratory-derived emission factors than wood stove emissions, due to lower dependence on user operation.

Health Effects of Operators in the Production of Wood Pellets

Energy Technology Data Exchange (ETDEWEB)

Hagstroem, K.; Arvidsson, H.; Bryngelsson, I.L.; Fedeli, C. [Oerebro Univ. (Sweden). Dept. of Occupational and Environmental Medicine; Eriksson, K. [Univ. Hospital of Umeaa (Sweden). Dept. of Occupational and Environmental Medicine; Andersson, E. [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Occupational and Environmental Medicine

2006-07-15

The environmental and energy policy in Sweden is aiming to replace fossil energy with renewable sources such as biofuels, e.g., wood Pellets produced from shavings and sawdust of pine and spruce. Reported health effects in the wood processing industries are airway, eye and skin irritation, reduced lung function as well as eczema. The aim of our study was to investigate the prevalence of airway and skin symptoms and measure lung function in a population of pellet operators in the Swedish wood industry. Additional reported acute effects from the airways, eyes, nose and skin were recorded. From May 2004 until April 2005 50 blue-collar workers from four Swedish pellet-producing industries were investigated. The study included a questionnaire about skin and airway symptoms (n=50), acute effect questionnaire (n=67; 44 individuals) as well as a test of the lung function (spirometry) before and after work shift (n=118; 39 individuals). Acute effects questionnaire and spirometry were done one to three times per participants and for the acute effects the worker had to assess their symptoms in the airways, eyes, nose and skin between 6 and 8 times during a day. The results from the symptom questionnaires were compared with reference data from other Swedish studies and the lung function data with a European reference material. Statistical tests used were chi-2-test for the questionnaire, t-test for lung function before shift compared expected values, and for difference in lung function between before and after work shift mixed models with subjects as a random factor. No statistical significant difference was seen for the skin and airway symptoms in the questionnaire. Reported acute effects were seen especially for eye and nose symptoms (table 1). Spirometry showed significantly higher forced vital capacity (FVC; p=0.0003) and no difference in forced expiratory volume in 1 second (FEV1; p=0.08) before work shift compared to expected values. FVC was 108,1 % and FEV1 was 104

Market study for the import of wood pellets from Russia to Finland

OpenAIRE

Ratkovskaya, Irina

2011-01-01

Traditional fuels - oil, gas and coal - are non-renewable energy sources, thus the world is looking for alternative fuels. Bioenergy is coming with a fast paste into the picture. Russia's prospects in the processing of bioenergy are almost unlimited, as the stocks of raw materials are huge. Pellets are a type of wood fuel that is produced from compacted sawdust under high pressure, without chemical fixers. Russian company Ltd. “BioCalorien”, located at the Leningrad Region, Podporozhje ...

Producing bio-pellets from sunflower oil cake for use as an energy source

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Yuichi; Kato, Hitoshi; Kanai, Genta; Togashi, Tatsushi [National Agricultural Research Center (Japan)], E-mail: kobay@affrc.go.jp

2008-07-01

Pellet fuels were produced from ground sunflower oil cake using a pelletizer. The length, hardness, and powder characteristics of dried pellets depend on the initial water content of the oil cake. The appropriate values of water contents were 19.9 - 21.0% w.b. Oil cake pellets were found to contain 6.07% ash and 20.99 MJ/kg caloric value, which are within the standard range of wood pellets. Combustion experiments using a commercial pellet stove demonstrate that oil cake pellets burn as well as wood pellets. Oil cake pellets are useful as a fuel alternative to wood pellets. (author)

Study of the feasibility of mixing Refuse Derived Fuels with wood pellets through the grey and Fuzzy theory

Energy Technology Data Exchange (ETDEWEB)

Moran, J.C.; Miguez, J.L.; Porteiro, J.; Patino, D.; Granada, E.; Collazo, J. [Universidad de Vigo E.T.S. Ingenieros Industriales, Lagoas-Marcosende, s/n. Dpto. Ing. Mecanica Maquinas y Motores Termicos, 36200 Vigo (Pontevedra) (Spain)

2009-12-15

This paper presents a combined grey relational and fuzzy analysis for the evaluation of the environmental feasibility of burning mixtures of pellet and RDF (Refuse Derived Fuel) in a small pellet boiler-stove. RDF is obtained from Municipal Solid Waste (MSW) and contains a biomass fraction and a non-organic fraction (plastic). As a first step, both fuels are characterized to define their properties. A special feeding system is also used to improve the stove plant and to facilitate pellet distribution, which maintains a constant rate between the two fuels. Small scale energy converters, such as chimneys, boilers, stoves, etc., which produce heat and/or hot water by burning biomass (wood, pellets, briquettes, etc.), are especially suited to domestic purposes. However, in common commercial combustion conditions, this kind of use still has some disadvantages: some emissions (volatile organic carbons, carbon monoxide or NO{sub x}) may still be high, and it is difficult to compare the quality and performance of equipment working in very different combustion conditions. The grey relational analysis of different energy and emission variables leads to the definition of a new single variable called the grey relational grade (GRG). Thus, evaluation and optimisation of complicated multiple responses can be converted into the optimisation of a standardised single variable. The aim of the work is to research the most feasible mixture of pellets according to a grey relational analysis, taking into consideration energy-related, financial and environmental aspects. (author)

Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications.

Science.gov (United States)

Rollinson, Andrew N; Williams, Orla

2016-05-01

Samples of torrefied wood pellet produced by low-temperature microwave pyrolysis were tested through a series of experiments relevant to present and near future waste to energy conversion technologies. Operational performance was assessed using a modern small-scale downdraft gasifier. Owing to the pellet's shape and surface hardness, excellent flow characteristics were observed. The torrefied pellet had a high energy density, and although a beneficial property, this highlighted the present inflexibility of downdraft gasifiers in respect of feedstock tolerance due to the inability to contain very high temperatures inside the reactor during operation. Analyses indicated that the torrefaction process had not significantly altered inherent kinetic properties to a great extent; however, both activation energy and pre-exponential factor were slightly higher than virgin biomass from which the pellet was derived. Thermogravimetric analysis-derived reaction kinetics (CO2 gasification), bomb calorimetry, proximate and ultimate analyses, and the Bond Work Index grindability test provided a more comprehensive characterization of the torrefied pellet's suitability as a fuel for gasification and also other combustion applications. It exhibited significant improvements in grindability energy demand and particle size control compared to other non-treated and thermally treated biomass pellets, along with a high calorific value, and excellent resistance to water.

Impact of fuel quality and burner capacity on the performance of wood pellet stove

Directory of Open Access Journals (Sweden)

Petrović-Bećirović Sanja B.

2015-01-01

Full Text Available Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8 and 10 kW, used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results obtained showed that in case of nominal load and combustion of pellets recommended by the stove manufacturer, stove efficiency of 80.03% was achieved. The use of lower quality pellet caused additional 1.13 kW reduction in heat output in case of nominal load and 0.63 kW in case of reduced load. This was attributed to less favourable properties and lower bulk and particle density of lower quality pellet. The use of different burner capacity has shown to have little effect on heat output and efficiency of the stove when pre-set values in the control system of the stove were not altered. It is concluded that replacement of the burner only is not sufficient to increase/decrease the declared capacity of the same stove configuration, meaning that additional measures are necessary. These measures include a new set up of the stove control system, which needs to be properly adjusted for each alteration in stove configuration. Without the adjustment mentioned, declared capacity of the stove cannot be altered, while its CO emission shall be considerably increased.

Ranking of lignocellulosic biomass pellets through multicriteria modeling

Energy Technology Data Exchange (ETDEWEB)

Sultana, A.; Kumar, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

2009-07-01

A study was conducted in which pellets from different lignocellulosic biomass sources were ranked using a multicriteria assessment model. Five different pellet alternatives were compared based on 10 criteria. The pair-wise comparison was done in order to develop preference indices for various alternatives. The methodology used in this study was the Preference Ranking Organization Method for Enrichment and Evaluation (PROMETHEE). The biomass included wood pellets, straw pellets, switchgrass pellets, alfalfa pellets and poultry pellets. The study considered both quantitative and qualitative criteria such as energy consumption to produce the pellets, production cost, bulk density, NOx emissions, SOx emissions, deposit formation, net calorific value, moisture content, maturity of technology, and quality of material. A sensitivity analysis was performed by changing weights of criteria and threshold values of the criteria. Different scenarios were developed for ranking cost and environmental impacts. According to preliminary results, the wood pellet is the best energy source, followed by switchgrass pellets, straw pellets, alfalfa pellets and poultry pellets.

Pellets - A fuel with a future

International Nuclear Information System (INIS)

2004-01-01

This special brochure presents a series of articles on the topic of wood pellets as a fuel of the future. Dr. Walter Steinmann, director of the Swiss Federal Office of Energy (SFOE) introduces the topic, stressing that the Swiss Confederation and the Cantons are supporting efforts to increase the sustainable use of wood fuels. Further articles take a closer look at pellets and their form. Pellets-fired heating units are introduced as a viable alternative to traditional oil-fired units. Tips are presented on the various ways of storing pellets. Quality-assurance aspects are examined and manufacturers and distributors of wood pellets are listed. A further article takes a closer look at a large Swiss manufacturer of pellets and describes the production process used as well as the logistics necessary for the transportation of raw materials and finished products. The brochure also presents a selection of pellet ovens and heating systems from various manufacturers. A further article illustrates the use of pellets as a means of heating apartment blocks built to the MINERGIE low-energy-consumption standard. In the example quoted, the classic combination of solar energy for the pre-heating of hot water and pellets for the central heating and hot water supply is used. The use of a buried spherical tank to store pellets - and thus the saving of space inside the building - is described in a further article that takes a look at the refurbishment of the heating system in a single-family home. Finally, various contributions presented at the Pellets Forum held in Berne in November 2003 are summarised in a short article

The environmental assessment of the wood combustion

International Nuclear Information System (INIS)

Dinca, Cristian; Badea, Adrian; Apostol, Tiberiu

2007-01-01

In this paper, the authors analysed the emissions from residential boilers burning wood logs, bark pellets, wood briquettes and wood pellets. Three boilers, selected with respect to age, design, connection to heat storage tank, and type of biofuel, were included in the study. The emissions captured comprised carbon monoxide (CO), carbon dioxide (CO 2 ), oxygen (O 2 ), total organic carbons (TOC), nitrogen oxides (NO x ), polycyclic aromatic hydrocarbons (PAC) and 33 volatile organic compounds (VOC). We have used the Life Cycle Inventory method in order to identify the main stressors generated by the wood combustion stage. In this purpose, we have analysed one type of old boiler, one type of modern boiler and a multi-fuel boiler, which can burn wood logs, bark pellets, wood briquettes and wood pellets. In this article, we selected only the wood combustion stage because it is the most important according to the emissions produced. (authors)

Pellet injector research and development at ORNL

International Nuclear Information System (INIS)

Combs, S.K.; Argo, B.E.; Baylor, L.R.; Cole, M.J.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Schechter, E.; Sparks, D.O.; Tsai, C.C.; Wilgen, J.B.; Whealton, J.W.

1993-01-01

A variety of pellet injector designs have been developed at ORNL including single-shot guns that inject one pellet, multiple-shot guns that inject four and eight pellets, machine gun-types (single- and multiple-barrel) that can inject up to >100 pellets, and centrifugal accelerators (mechanical devices that are inherently capable of high repetition rates and long-pulse operation). With these devices, macroscopic pellets (1--6 mm in diameter) composed of hydrogen isotopes are typically accelerated to speeds of ∼1.0 to 2.0 km/s for injection into plasmas of experimental fusion devices. In the past few years, steady progress has been made at ORNL in the development and application of pellet injectors for fueling present-day and future fusion devices. In this paper, we briefly describe some research and development activities at ORNL, including: (1) two recent applications and a new one on large experimental fusion devices, (2) high-velocity pellet injector development, and (3) tritium injector research

LCA calculations on Swedish wood pellet production chains - according to the Renewable Energy Directive

Energy Technology Data Exchange (ETDEWEB)

Hagberg, Linus; Saernholm, Erik; Gode, Jenny; Ekvall, Tomas; Rydberg, Tomas

2009-09-15

The study includes calculations of typical life cycle emissions of greenhouse gases for representative Swedish pellet production chains in accordance with the calculation rules in RED (Directive 2009/28/EC). The study also intends to analyse how the directive is applicable on solid biofuels in general and on wood pellet production in particular, and to identify such aspects of the methodology in RED that are associated with obscurities, problems or lead to misleading results compared to other life cycle analysis principles. The report includes a large number of alternative calculations to show how different facts, assumptions and methodological choices affect the results. This includes the effect of what fuels are used for drying, different transport distances, assumed fuel mix for purchased electricity, the variance in efficiency between the investigated plants as well as the effect of different interpretations of the RED methodology for greenhouse gas calculations

Pellets standard on the way

International Nuclear Information System (INIS)

Laeng, H.-P.

2001-01-01

This short article introduces the Swiss standard that has been adapted from the German standard for heating pellets made of untreated wood. The various requirements placed on the materials used in the manufacture of the pellets and their influence on the pollution emissions produced by boilers and ovens using the pellets as a heating fuel are listed. Further points in the standard referring to declarations to be made by the manufacturer, size and specific weight of the pellets and instructions for the storage and burning of the pellets are discussed

Density, heating value, and composition of pellets made from lodgepole pine (Pinus concorta Douglas) infested with mountain pine beetle (Dendroctonus ponderosae Hopkins)

Energy Technology Data Exchange (ETDEWEB)

Zaini, P.; Kadla, J. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Wood Science; Sokansanj, S. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Oak Ridge National Laboratory, Oak Ridge, TN (United States). Environmental Sciences Div., Bioenergy Resource and Engineering Systems; Bi, X.; Lim, C.J. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Mani, S. [Georgia Univ., Athens, GA (United States). Faculty of Engineering; Melin, S. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Delta Research Corp., Delta, BC (Canada)

2008-07-01

BC is currently experiencing the largest recorded mountain pine beetle (MPB) infestation in North America that has killed nearly 7 million hectares of pine. The dead trees gradually lose their suitability for dimension lumber and pulp chips due to excessive cracking and spoilage. The economic losses can be partly averted by recovering the killed wood and processing it into pellets for bioenergy and other applications. Currently, Canada exports roughly 750,000 tons of wood pellets to Europe as a fuel for heat and power. The most important physical properties of wood pellets are bulk and pellet density, heating value, moisture content, and durability. In light of the chemical and structural changes reported with MPB attack, it is important to develop engineering data on properties of MPB-affected pine for wood pellets. The objective of this study was to compare chemical composition, density, and heat value of pellets made from MPB-infested wood and to compare these properties with those measured for pellets made from uninfested wood. Chemical analysis showed minor decrease in lignin and sugar contents of pellets made from MPB wood. Pellets made from MPB-infested pine had a mean value for density larger than those made from uninfested pine but the difference was not statistically significant. Heating values of the pellets from MPB-infested wood were similar to those measured for pellets from uninfested wood. A preliminary observation of mold growth did not show any further staining or other decay fungi growth for the pellets made from MPB-infested wood. The pellets made from MPB-infested wood were found to be similar to pellets made from uninfested wood in density, heating value, and most chemical constituents. The overall conclusion was that MBP infested wood can be used to produce comparable pellets to non infested wood pellets. 37 refs., 6 tabs., 2 figs.

Environmentally adapted energy production and working environment. Manufacture of wood pellets; Miljoeanpassad energiproduktion och arbetsmiljoe. Tillverkning av traepellets

Energy Technology Data Exchange (ETDEWEB)

Alvarez de Davila, Eliana

2002-04-01

The working environment at three wood pellet production plants was studied. Measurements were made of dust, microorganisms (bacteria and molds) and terpenes. Both stationary and personal sampling equipment were used. Dust sources and dust diffusion were mapped. Work in the raw material storage rooms and at the semi-automatic sack-filling stations can give high exposure to wood dusts (max. 4.7 mg/m{sup 3}). These high levels might cause irritations in the respiratory tract. Relatively high levels of terpenes were detected in the plant that did not dry wood shavings or sawdust. Pressing of non-dried shavings probably leads to emission of terpenes and other gaseous substances in the plant. Recommendations for improvements of the working conditions are given in the report.

Pelletizing properties of torrefied spruce

DEFF Research Database (Denmark)

Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.

2011-01-01

analysis revealed a cohesive failure mechanism due to strong inter-particle bonding in spruce pellets as a resulting from a plastic flow of the amorphous wood polymers, forming solid polymer bridges between adjacent particles. Fracture surfaces of pellets made from torrefied spruce possessed gaps and voids...

Chimney emissions from small-scale burning of pellets and fuelwood - examples referring to different combustion appliances

International Nuclear Information System (INIS)

Kjaellstrand, Jennica; Olsson, Maria

2004-01-01

Most wood boilers used for residential heating today are old-fashioned and emit large quantities of organic compounds. The installation of a pellet burner and a change to wood pellets as fuel normally decreases the emissions remarkably. In this study, the emissions from different equipment for burning of wood and pellets are compared. The organic fraction of smoke from traditional wood burning is to a great extent composed of methoxyphenols, with antioxidant effects. Methoxyphenols were also identified in smoke from pellet stoves. A fuel wood boiler or a furnace with an inserted pellet burner is heated to a higher combustion temperature, decreasing the total amount of organic compounds in the smoke. Above 800 deg C, methoxyphenols are thermally decomposed and carcinogenic polycyclic aromatic compounds (PACs) are formed. The combustion-formed aromatic hydrocarbon benzene is present in smoke from all kinds of burning, but the proportion relative to primary organic compounds increases with increasing combustion temperature. In smoke from an environmentally labelled wood boiler and from some pellet burning devices, the levels of PAC and benzene were found to be low. Evidently, the combustion was nearly complete. Although the change from wood to pellets significantly decreases the emissions, considerable differences exist between various combinations of pellet burners and boiler furnaces. (Author)

Chapter 6: Wood energy and competing wood product markers

Science.gov (United States)

Kenneth E. Skog; Robert C. Abt; Karen Abt

2014-01-01

Understanding the effect of expanding wood energy markets is important to all wood-dependent industries and to policymakers debating the implementation of public programs to support the expansion of wood energy generation. A key factor in determining the feasibility of wood energy projects (e.g. wood boiler or pellet plant) is the long-term (i.e. 20-30year) supply...

Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

Science.gov (United States)

Wolfgang Stelte; Craig Clemons; Jens K. Holm; Jesper Ahrenfeldt; Ulrik B. Henriksen; Anand R. Sanadi

2012-01-01

The utilization of wheat straw as a renewable energy resource is limited due to its low bulk density. Pelletizing wheat straw into fuel pellets of high density increases its handling properties but is more challenging compared to pelletizing wood biomass. Straw has a lower lignin content and a high concentration of hydrophobic waxes on its outer surface that may limit...

Power from Pellets Technology and Applications

CERN Document Server

Döring, Stefan

2013-01-01

This book provides a practical description of the technology of pellet production on the basis of renewable sources as well as the utilization of pellets. The author explains what kinds of biomass are usable in addition to wood, how to produce pellets and how to use pellets to produce energy. Starting with the basics of combustion, gasification and the pelletizing process, several different technologies are described. The design, planning, construction and economic efficiency are discussed as well. The appendix gives useful advice about plant concepts, calculations, addresses, conversion tables and formulas.

Wood torrefaction. Pilot tests and utilisation prospects

Energy Technology Data Exchange (ETDEWEB)

Wilen, C.; Jukola, P.; Jarvinen, T.; Sipila, K. [VTT Technical Reseach Centre of Finland, Espoo (Finland); Verhoeff, F.; Kiel, J. [Energy research Centre of the Netherlands, LE Petten (Netherlands)

2013-09-15

The research project 'Torrefaction of woody biomasses as energy carriers for the European markets' was carried out within the Tekes BioRefine programme in 2010-2012 and was coordinated by VTT. The main objective of the project was to create a discussion platform and collate basic information for the Finnish industrial stakeholders involved in developing torrefaction technology or planning to include torrefied biomass in their fuel supply for energy production. Given the availability of torrefaction pilot facilities in Europe, it was decided at an early phase of the national torrefaction research project not to build and operate separate pilot equipment, and thus save time and money. Experimental research was conducted in cooperation with ECN, The Netherlands. Finnish wood chips and crushed forest residue were tested at different torrefaction temperatures in the PATRIG torrefaction test rig with great success, and large quantities of torrefied wood chips and pellets were produced. CFD simulation work was carried out at VTT to investigate the feasibility of torrefied fuels to replace part of the coal. From the combustion point of view it seems feasible to replace coal by torrefied wood biomass with shares up to 50% by weight. Basic, small-scale experiments were carried out to compare torrefied wood pellets with conventional wood and straw pellets with regard to their handling and storage properties. The experiments showed that the torrefied pellets are clearly more hydrophobic than wood and straw pellets and do not disintegrate completely on exposure to water. A study on dust explosion and self-ignition characteristics indicated that the torrefied dust does not differ significantly from the normal biomass dust, but is clearly more reactive than coal dust. Commercial development of torrefaction is currently in its early phase. The current general view is that most of the demonstration plants have technical problems, which have delayed their commercial

Development of an eco- and material-efficient pellet production chain. A chemical study

Energy Technology Data Exchange (ETDEWEB)

Kuokkanen, M.

2013-06-01

According to the EU's strategy and the corresponding Finnish national strategy on waste materials, all kinds of waste must be utilised primarily as material (reuse, recycling) and secondarily as energy, and at the lowest level of waste hierarchy is their disposal using environmentally friendly methods. Today material efficiency is an essential topic in promoting sustainable use of natural resources, industrial by-products and waste material. The present goal proposed by the EU sets the target for the total proportion of renewable energy as high as 38% by 2020 in Finland. Up to 20 million tonnes of waste wood biomass per year are left unused in Finland, mainly in the forests during forestry operations, because supply and demand do not meet. As a consequence of high heat energy prices, the looming threat of climate change, the greenhouse effect and global as well as national demands to considerably increase the proportion of renewable energy, Finland currently has a tremendous interest in increasing decentralised pellet production alongside of large-scale factories. The aim of this thesis is to promote the development of eco-, material- and cost-efficient Nordic wood-based pellet production and utilisation of pellet bio-ash by means of chemical research. Using Finnish wood (sawdust and shavings) as a model raw material, the total functionality of a pilot-scale pellet facility combined with an extensive chemical toolbox was tested in this study to promote development of an eco-, material- and cost-efficient wood-based pellet production chain. The chemical toolbox includes measurements of moisture content, density, heat value, mechanical durability and particle size distribution, TG analysis and elementary analysis, as well as new applications for pellet biodegradation using BOD OxiTop equipment and optical microscopic staining methods. To improve the quality of pellets, considering the profitability of production and occupational safety factors (wood dust

Microbial Communities in Sunken Wood Are Structured by Wood-Boring Bivalves and Location in a Submarine Canyon

Science.gov (United States)

Fagervold, Sonja K.; Romano, Chiara; Kalenitchenko, Dimitri; Borowski, Christian; Nunes-Jorge, Amandine; Martin, Daniel; Galand, Pierre E.

2014-01-01

The cornerstones of sunken wood ecosystems are microorganisms involved in cellulose degradation. These can either be free-living microorganisms in the wood matrix or symbiotic bacteria associated with wood-boring bivalves such as emblematic species of Xylophaga, the most common deep-sea woodborer. Here we use experimentally submerged pine wood, placed in and outside the Mediterranean submarine Blanes Canyon, to compare the microbial communities on the wood, in fecal pellets of Xylophaga spp. and associated with the gills of these animals. Analyses based on tag pyrosequencing of the 16S rRNA bacterial gene showed that sunken wood contained three distinct microbial communities. Wood and pellet communities were different from each other suggesting that Xylophaga spp. create new microbial niches by excreting fecal pellets into their burrows. In turn, gills of Xylophaga spp. contain potential bacterial symbionts, as illustrated by the presence of sequences closely related to symbiotic bacteria found in other wood eating marine invertebrates. Finally, we found that sunken wood communities inside the canyon were different and more diverse than the ones outside the canyon. This finding extends to the microbial world the view that submarine canyons are sites of diverse marine life. PMID:24805961

Waste wood as bioenergy feedstock. Climate change impacts and related emission uncertainties from waste wood based energy systems in the UK.

Science.gov (United States)

Röder, Mirjam; Thornley, Patricia

2018-04-01

Considering the urgent need to shift to low carbon energy carriers, waste wood resources could provide an alternative energy feedstock and at the same time reduce emissions from landfill. This research examines the climate change impacts and related emission uncertainties of waste wood based energy. For this, different grades of waste wood and energy application have been investigated using lifecycle assessment. Sensitivity analysis has then been applied for supply chain processes and feedstock properties for the main emission contributing categories: transport, processing, pelletizing, urea resin fraction and related N 2 O formation. The results show, depending on the waste wood grade, the conversion option, scale and the related reference case, that emission reductions of up to 91% are possible for non-treated wood waste. Compared to this, energy from treated wood waste with low contamination can achieve up to 83% emission savings, similar to untreated waste wood pellets, but in some cases emissions from waste wood based energy can exceed the ones of the fossil fuel reference - in the worst case by 126%. Emission reductions from highly contaminated feedstocks are largest when replacing electricity from large-scale coal and landfill. The highest emission uncertainties are related to the wood's resin fraction and N 2 O formation during combustion and, pelletizing. Comparing wood processing with diesel and electricity powered equipment also generated high variations in the results, while emission variations related to transport are relatively small. Using treated waste wood as a bioenergy feedstock can be a valid option to reduce emissions from energy production but this is only realisable if coal and landfill gas are replaced. To achieve meaningful emission reduction in line with national and international climate change targets, pre-treatment of waste wood would be required to reduce components that form N 2 O during the energy conversion. Copyright © 2017

Pellet injector research and development at ORNL

International Nuclear Information System (INIS)

Combs, S.K.; Barber, G.C.; Baylor, L.R.

1994-01-01

Oak Ridge National Laboratory has been developing pellet injectors for plasma fueling experiments on magnetic confinement devices for more than 15 years. Recent major applications of the ORNL development program include (1) a tritium-compatible four-shot pneumatic injector for the Tokamak Fusion Test Reactor, (2) a centrifuge pellet injector for the Tore Supra tokamak, and most recently (3) a three-barrel repeating pneumatic injector for the DIII-D tokamak. In addition to applications, ORNL is developing advanced technologies, including high-speed pellet injectors, tritium injectors, and long-pulse pellet feed systems. The high-speed research involves a collaboration between ORNL and ENEA-Frascati in the development of a repeating two-stage light gas gun based on an extrusion-type pellet feed system. Construction of a new tritium-compatible, extruder-based repeating pneumatic injector (8-mm-diam) is complete and will replace the pipe gun in the original tritium proof-of-principle experiment. The development of a steady-state feed system in which three standard extruders operate in tandem is under way. These research and development activities are relevant to the International Thermonuclear Experimental Reactor and are briefly described in this paper

Steam-treated wood pellets: Environmental and financial implications relative to fossil fuels and conventional pellets for electricity generation

International Nuclear Information System (INIS)

McKechnie, Jon; Saville, Brad; MacLean, Heather L.

2016-01-01

Highlights: • Steam-treated pellets can greatly reduce greenhouse gas emissions relative to coal. • Cost advantage is seen relative to conventional pellets. • Higher pellet cost is more than balanced by reduced retrofit capital requirements. • Low capacity factors further favour steam-treated pellets over conventional pellets. - Abstract: Steam-treated pellets can help to address technical barriers that limit the uptake of pellets as a fuel for electricity generation, but there is limited understanding of the cost and environmental impacts of their production and use. This study investigates life cycle environmental (greenhouse gas (GHG) and air pollutant emissions) and financial implications of electricity generation from steam-treated pellets, including fuel cycle activities (biomass supply, pellet production, and combustion) and retrofit infrastructure to enable 100% pellet firing at a generating station that previously used coal. Models are informed by operating experience of pellet manufacturers and generating stations utilising coal, steam-treated and conventional pellets. Results are compared with conventional pellets and fossil fuels in a case study of electricity generation in northwestern Ontario, Canada. Steam-treated pellet production has similar GHG impacts to conventional pellets as their higher biomass feedstock requirement is balanced by reduced process electricity consumption. GHG reductions of more than 90% relative to coal and ∼85% relative to natural gas (excluding retrofit infrastructure) could be obtained with both pellet options. Pellets can also reduce fuel cycle air pollutant emissions relative to coal by 30% (NOx), 97% (SOx), and 75% (PM 10 ). Lesser retrofit requirements for steam-treated pellets more than compensate for marginally higher pellet production costs, resulting in lower electricity production cost compared to conventional pellets ($0.14/kW h vs. $0.16/kW h). Impacts of retrofit infrastructure become increasingly

European wood-fuel trade

International Nuclear Information System (INIS)

Hillring, B.; Vinterbaeck, J.

2001-01-01

This paper discusses research carried out during the l990s on European wood fuel trade at the Department of Forest Management and Products, SLU, in Sweden. Utilisation of wood-fuels and other biofuels increased very rapidly in some regions during that period. Biofuels are replacing fossil fuels which is an effective way to reduce the future influence of green house gases on the climate. The results indicate a rapid increase in wood-fuel trade in Europe from low levels and with a limited number of countries involved. The chief products traded are wood pellets, wood chips and recycled wood. The main trading countries are, for export, Germany and the Baltic states and, for import, Sweden, Denmark and to some extent the Netherlands. In the future, the increased use of biofuel in European countries is expected to intensify activity in this trade. (orig.)

Emissions from wood domestic heating appliances

International Nuclear Information System (INIS)

Collet, S.

2009-01-01

Much research has been carried out to study emissions from wood domestic heating appliances. This work reviews the available emission factors about pollutants produced in different types of wood domestic heating appliances. The main sources of pollutants are older stoves that in most cases are used as an additional heating appliance. These stoves causes higher emissions than modern appliances. Then, substitution of an old type wood appliance with a modern appliance or boiler or a pellet boilers, would reduce considerably emissions in this sector. The efficiency of this measure is estimated for each pollutant. (author)

Feasibility study for new ecolabels for the product group: Wood pellet firings. Final report; Machbarkeitsstudie fuer neue Umweltzeichen fuer die Produktgruppe: Holzpelletfeuerungen. Endbericht

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, E.; Weiss, J.; Hirschl, B.

2002-07-01

This assessment is a feasibility study according to ISO 14024. It deals with the question whether an ecolabel is suitable for wood pellet heating systems and how concrete criteria for an ecolabel for wood pellet heating plants could be specified. The study begins with a comprehensive market analysis in order to identify possible plants for which an ecolabel would make sense. In the main part of the study, the environmental relevance of the chosen plants is analysed. For this analysis, plant manufacturers were interviewed and a comparison between wood pellet heating systems and heating systems which use gas, oil or wood was carried out. On the basis of this analysis, it was possible to derive a number of criteria which were discussed with company representatives and other experts in this field. As a result of this dialogue and the investigation process as a whole, the introduction of an ecolabel for wood pellet heating plants can be recommended. Wood pellet heating systems are characterized by their high level of automatation and the use of standardized fuels with constant high quality. Thus, they reach high combustion quality with low emission rates, and risks of misuse are minimized. They may contribute to the increased use of renewable energies and thereby to the achievement of climate protection goals. The proposed certification principles comprise requirements regarding (a) the efficient energy use (efficiency factor under partial load and nominal load, plant's supplementary energy consumption), (b) emission values for CO, NO{sub x}, dust and organic substances, (c) the offer of additional services, as well as (d) requirements with regard to the operating instructions. The transcription of the label is proposed as 'Ecolabel.. because low emission and energy-efficient'. (orig.) [German] Beim vorliegenden Gutachten handelt es sich um eine Machbarkeitsstudie nach ISO 14024. Es behandelt die Frage, ob ein Umweltzeichen fuer Holzpelletfeuerungen

Exposure conditions, lung function and airway symptoms in industrial production of wood pellets. A pilot project; Exponeringsfoerhaallanden, lungfunktion och luftvaegsbesaer vid industriell produktion av traepellets. Ett pilotprojekt

Energy Technology Data Exchange (ETDEWEB)

Edman, Katja; Loefstedt, Haakan; Berg, Peter; Bryngelsson, I.L.; Fedeli, Cecilia; Selden, Anders [Oerebro Univ. Hospital (Sweden). Yrkes- och miljoemedicinska kliniken; Eriksson, Kaare [Umeaa Univ. Hospital (Sweden); Holmstroem, Mats; Rask- Andersen, Anna [Uppsala Univ. Hospital (Sweden)

2002-02-01

The production of wood pellets is a relatively new branch of the Swedish wood industry and has increased during the last years. A pilot study was performed to investigate the prevalence of airway symptoms, lung function and exposure among all 39 men employed in industrial production of wood pellets at six companies. The study included a questionnaire, medical examination, registration of nasal-PEF (peak expiratory flow) during a week, allergy screening (Phadiatop) and lung function (spirometry) before and after work shift. The results were compared with different reference data from other Swedish studies. Exposure measurements of monoterpenes and wood dust on filter and with a data logger (DataRAM) were also performed. The study group reported a higher frequency of cough without phlegm, awakening due to breathlessness and current asthma medication compared with reference data. For five of the six participants with physician-diagnosed asthma the disease debuted before the current employment and the results did not indicate an unusual asthma morbidity. Spirometry showed lower lung function before work shift than expected. However no difference over work shift was observed. A negative and non-significant correlation was seen between time with current work task and lung function. The study group reported a higher frequency of nasal symptoms mostly blockage, sneezing and dryness compared with reference data. The registrations of nasal-PEF did not show any differences between work and spare time. The prevalence of positive Phadiatop (23 %) did not differ from reference data. No association between exposure (wood dust and monoterpenes) and acute effects on lung function was observed. The wood dust exposure (0.16-19 mg/m{sup 3}) was high and 11 of 24 measurements exceeded the present Swedish occupational exposure limit of 2 mg/m{sup 3}. Peak exposures could be identified, e.g. at cleaning of engines with compressed air, with the DataRAM. The exposure to monoterpenes (0

Pellet fired appliances. Market survey. 7. rev. ed.; Pelletheizungen. Marktuebersicht

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-01-15

The market survey under consideration reports on pellet central heating systems and pellet fired appliances. The main chapters of this market survey are concerned to: (1) Information on wood pellets and pellet fired appliances; (2) Information about the interpretation of the market survey; (3) Survey of all compared pellet fired appliances with respect to the nominal power; (4) Price lists of pellet fired appliances and pellet central heating systems; (5) Type sheets of the compared pellet fired appliances and pellet central heating systems. Finally, this brochure contains the addresses of the produces and distribution partners of pellet fired appliances and pellet central heating systems.

Potential of pelleted wheat straw as an alternative bedding material for broilers.

Science.gov (United States)

Kheravii, S K; Swick, R A; Choct, M; Wu, S-B

2017-06-01

Broiler chickens are commonly placed on wood shavings as litter, but alternative litter sources are required due to the scarcity of wood shavings in many parts of the world. This study aimed to compare pelleted straw, chopped wheat straw, wood shavings, rice hulls, and shredded paper as litter candidates. Three-hundred-sixty Ross 308 one-day-old male chicks were used in this study. There were 5 litter treatments with 6 replicate pens, each with 12 birds. The feed conversion ratio (FCR) of birds reared on pelleted straw was improved compared (P Litter source did not affect the occurrence of breast blisters at d 24, 29, or 35. On d 24, 29, and 35, pelleted straw litter was less caked than chopped straw and shredded paper (P broiler health, performance, and welfare are needed to determine the economic benefits of pelleted litter. © 2017 Poultry Science Association Inc.

Wood Protection Research Council: Research Priorities 2013

Science.gov (United States)

Carol A Clausen; Frederick Green III; Grant T. Kirker; Stan T. Lebow

2014-01-01

This report summarizes presentations and comments from the inaugural Wood Protection Research Council meeting. Research needs for the wood protection industry were identified and prioritized. Methods for successfully addressing research needs were discussed by industry, academia, and association representatives.

Gasification of Wood and Non-wood Waste of Timber Production as Perspectives for Development of Bioenergy

Science.gov (United States)

Kislukhina, Irina A.; Rybakova, Olga G.

2018-03-01

The article deals with biomass gasification technology using the gasification plant running on wood chips and pellets, produced from essential oils waste (waste of coniferous boughs). During the study, the authors solved the process task of improving the quality of the product gas derived from non-wood waste of timber production (coniferous boughs) due to the extraction of essential oils and the subsequent thermal processing of spent coniferous boughs at a temperature of 250-300°C degrees without oxygen immediately before pelleting. The paper provides the improved biomass gasification process scheme including the grinding of coniferous boughs, essential oil distillation and thermal treatment of coniferous boughs waste and pelletizing.

Trial production of fuel pellet from Acacia mangium bark waste biomass

Science.gov (United States)

Amirta, R.; Anwar, T.; Sudrajat; Yuliansyah; Suwinarti, W.

2018-04-01

Fuel pellet is one of the innovation products that can be produced from various sources of biomass such as agricultural residues, forestry and also wood industries including wood bark. Herein this paper, the potential fuel pellet production using Acacia mangium bark that abundant wasted from chip mill industry was studied. Fuel pellet was produced using a modified animal feed pellet press machine equipped with rotating roller-cylinders. The international standards quality of fuel pellet such as ONORM (Austria), SS (Sweden), DIN (Germany), EN (European) and ITEBE (Italy) were used to evaluate the optimum composition of feedstock and additive used. Theresults showed the quality offuel pellet produced were good compared to commercial sawdust pellet. Mixed of Acacia bark (dust) with 10% of tapioca and 20% of glycerol (w/w) was increased the stable form of pellet and the highest heating value to reached 4,383 Kcal/kg (calorific value). Blending of Acacia bark with tapioca and glycerol was positively improved its physical, chemical and combustion properties to met the international standards requirement for export market. Based on this finding, production of fuel pellet from Acacia bark waste biomass was promising to be developed as an alternative substitution of fossil energy in the future.

Ranking of biomass pellets by integration of economic, environmental and technical factors

International Nuclear Information System (INIS)

Sultana, Arifa; Kumar, Amit

2012-01-01

Interest in biomass as a renewable energy source has increased recently in response to a need to reduce greenhouse gas (GHG) emissions. The objective of this study is to develop a multi-criteria assessment model and rank different biomass feedstock-based pellets, in terms of their suitability for use in large heat and power generation plants and show the importance of environmental, economical and technical factors in making decision about different pellets. Five pellet alternatives, each produced from a different sustainable biomass feedstock i.e., wood, straw, switchgrass, alfalfa and poultry litter, are ranked according to eleven criteria, using the Preference Ranking Organization Method for Enrichment and Evaluation (PROMETHEE). Both quantitative and qualitative criteria are considered, including environmental, technical and economic factors. Three scenarios, namely base case, environmental and economic, are developed by changing the weight assigned to different criteria. In the base case scenario, equal weights are assigned to each criterion. In the economic and environmental scenarios, more weight is given to the economic and environmental factors, respectively. Based on the PROMETHEE rankings, wood pellets are the best source of energy for all scenarios followed by switchgrass, straw, poultry litter and alfalfa pellets except economic scenario, where straw pellets held higher position than switchgrass pellets. Sensitivity analysis on weights, threshold values, preference function and production cost indicate that the ranking was stable. The ranking in all scenarios remained same when qualitative criteria were omitted from the model; this indicates the stronger influence of quantitative criteria. -- Highlights: ► This study ranks the pellets produced from different biomass feedstocks. ► The ranking of the pellets is based on technical, economical and environmental factors. ► This study uses PROMETHEE method for ranking pellets based on a range of

Emissions from burning of softwood pellets

International Nuclear Information System (INIS)

Olsson, Maria; Kjaellstrand, Jennica

2004-01-01

Softwood pellets from three different Swedish manufacturers were burnt in laboratory scale to determine compounds emitted. The emissions were sampled on Tenax cartridges and assessed by gas chromatography and mass spectrometry. No large differences in the emissions from pellets from different manufacturers were observed. The major primary semi-volatile compounds released during flaming burning were 2-methoxyphenols from lignin. The methoxyphenols are of interest due to their antioxidant effect, which may counteract health hazards of aromatic hydrocarbons. Glowing combustion released the carcinogenic benzene as the predominant aromatic compound. However, the benzene emissions were lower than from flaming burning. To relate the results from the laboratory burnings to emissions from pellet burners and pellet stoves, chimney emissions were determined for different burning equipments. The pellet burner emitted benzene as the major aromatic compound, whereas the stove and boiler emitted phenolic antioxidants together with benzene. As the demand for pellets increases, different biomass wastes will be considered as raw materials. Ecological aspects and pollution hazards indicate that wood pellets should be used primarily for residential heating, whereas controlled large-scale combustion should be preferred for pellets made of most other types of biomass waste. (Author)

Small Landowner Production of Pellets from Green, Beetle-Killed, and Burned Lodgepole Pine

Directory of Open Access Journals (Sweden)

Xuexian Qin

2018-03-01

Full Text Available To meet the growing need for raw materials to produce pellets and wood-based biofuels, trees killed by natural disturbances have increasingly been considered as potential feedstock in bioenergy development scenarios in the Western U.S. and Canada. While much research has focused on utilization of beetle-killed and fire-salvaged timber from federal lands in this region, small private landowners make up a large portion of land holdings in the Rocky Mountain Region and may also provide an important potential supply of uniform feedstock pellets in decentralized energy supply systems in the future. In this paper, we evaluated the quality of pellets produced from green, beetle-killed, and burned lodgepole pine with and without bark using a chipper, hammer mill, and pellet mill intended for use by small landowners. Results show that green, beetle-killed, and fire-salvaged lodgepole pine produced by small landowners, including material with bark, are suitable as feedstock for pellet production. Further, pellet quality can be varied through the blending of source lodgepole pine products when needed to meet pellet quality standards.

Continued growth expected for wood energy despite turbulence of the economic crisis : wood energy markets, 2008-2009

Science.gov (United States)

Rens Hartkamp; Bengt Hillring; Warren Mabee; Olle Olsson; Kenneth Skog; Henry Spelter; Johan Vinterback; Antje Wahl

2009-01-01

The economic crisis has not reduced the demand for wood energy, which is expected to continue to grow. The downturn in sawmill production caused a shortage of raw material supply for wood pellet producers. With decreased demand for pulpwood-quality roundwood for wood and paper products in 2009, some pulpwood is being converted into wood energy. Economies of scale are...

A look at worldwide usage of residual wood for energy

International Nuclear Information System (INIS)

Ekstrom, H.; Hall, M.M.

2007-01-01

Wood Resources International was established in 1987, offering on-site evaluation services of forest resources and forest industry developments in over 20 countries worldwide. This presentation reviewed residual wood markets in North America and Europe. Wood chip trade and wood pellet markets were also reviewed. It is estimated that more than 50 per cent of the wood harvested worldwide is used for heating and cooking. Although sawmill wood residue has been typically used for particle board manufacturing, the energy sector in North America and Europe is now competing for low cost residuals, including sawdust, shavings and wood chips. With demand for renewable resources increasing, district heating plants have revived an interest in collecting the nearly 35 per cent of biomass left behind after traditional clear cutting. This biomass represents branches, tops and stumps left behind after the roundwood has been removed. In Canada, demand for mill residuals has grown and wood pellet manufacturers have the opportunity to invest in capacity while continuing to produce competitively priced pellets for the European market. It is anticipated that in the next decade, large volumes of beetle-killed wood are going to be available in British Columbia for energy consumption, including wood pellet production. Prices for sawdust have doubled over the past 3 years as a result of increased competition. The biomass supply potential in the United States is 7 times the current consumption. There is an increased interest in bioenergy in California due to the declining lumber sector. As such, the use of forest and agricultural waste is on the rise, along with prices for wood residues. There has also been a large increase in demand for wood biomass in Europe over the past 5 years, resulting in higher costs of all wood fiber sources used for energy. By 2020, Europe has set a target that all energy should come from renewable energy sources, with a minimum of 10 per cent being biofuel for

Feasibility study for new ecolabels according to ISO 14024 (type 1) within the product group: wood pellet heating systems; Machbarkeitsstudie fuer neue Umweltzeichen fuer die Produktgruppe: Holzpelletfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, E.; Weiss, J.; Hirschl, B. [Institut fuer Oekologische Wirtschaftsforschung (IOEW) gGmbH, Berlin (Germany)

2003-01-01

This assessment is a feasibility study according to ISO 14024. It deals with the question whether an ecolabel is suitable for wood pellet heating systems and how concrete criteria for an ecolabel for wood pellet heating plants could be specified. The study begins with a comprehensive market analysis in order to identify possible plants for which an ecolabel would make sense. In the main part of the study, the environmental relevance of the chosen plants is analysed. For this analysis, plant manufacturers were interviewed and a comparison between wood pellet heating systems and heating systems which use gas, oil or wood was carried out. On the basis of this analysis, it was possible to derive a number of criteria which were discussed with company representatives and other experts in this field. As a result of this dialogue and the investigation process as a whole, the introduction of an ecolabel for wood pellet heating plants can be recommended. Wood pellet heating systems are characterized by their high level of automatation and the use of standardized fuels with constant high quality. Thus, they reach high combustion quality with low emission rates, and risks of misuse are minimized. They may contribute to the increased use of renewable energies and thereby to the achievement of climate protection goals. The proposed certification principles comprise requirements regarding (a) the efficient energy use (efficiency factor under partial load and nominal load, plant's supplementary energy consumption), (b) emission values for CO, NO{sub x}, dust and organic substances, (c) the offer of additional services, as well as (d) requirements with regard to the operating instructions. The transcription of the label is proposed as 'Ecolabel.. because low emission and energy-efficient'. (orig.) [German] Beim vorliegenden Gutachten handelt es sich um eine Machbarkeitsstudie nach ISO 14024. Es behandelt die Frage, ob ein Umweltzeichen fuer Holzpelletfeuerungen

Development and problems of pellet markets in Austria

International Nuclear Information System (INIS)

Nemestothy, K.P.; Rakos, C.

2001-01-01

Wood pellets became into Austrian markets in 1994. Up to then the Austrian industry had manufactured pellet fireplaces for export, but none was sold into Austria, because there were not pellets available in the Austrian markets. In spite of significant problems in the beginning and unfavourable economic conditions (decrease of oil prices) the pellet markets in Austria have increased since 1996 dynamically. Annual pellet deliveries have increased from 15 000 t/a to present 45 000 t/a. Customers and Austrian industry are interested in pellets and they believe in the future. The pellet manufacturing capacity increases continuously. In 1999 the capacity of 12 companies was 120 000 t. In 2003 the annual pellet consumption is estimated to over 100 000 tons and in 2010 about 200 000 tons. Main portion of the pellet manufactures in Austria is also used in the country by detached houses and small real estate houses. The pellet markets for large real estates are developing after the boiler manufacturers have started to produce pellet-fired equipment. The number of pellet-fired devices in 1997, sold to detached houses was 425, and in 2000 the number was 3500

Fuel Pellets from Biomass. Processing, Bonding, Raw Materials

DEFF Research Database (Denmark)

Stelte, Wolfgang

in an increasing interest in biomass densification technologies, such as pelletization and briquetting. The global pellet market has developed quickly, and strong growth is to be expected for the coming years. Due to an increasing demand for biomass, the traditionally used wood residues from sawmills and pulp...... influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet...... surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding...

Variations in the wood raw material for pellets manufacture and its influence on the quality of wood pellets; Variationer inom traeraavaran foer pelletstillverkning och deras paaverkan paa pelletskvaliteten

Energy Technology Data Exchange (ETDEWEB)

Jirjis, Raida; Vinterbaeck, Johan; Engberg, Jessica [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Bioenergy; Oehman, Marcus [ETC Energitekniskt Centrum, Piteaa (Sweden)

2002-05-01

The aim of this project was to study the variations in properties of raw material and its effect on pellets quality. The project included three parts which together would help describe the relationship between material properties, process parameters and fuel quality. The first part dealt with a small-scale production of pellets using a well defined raw material. The objectives of this part were to study the effect of tree species, stem diameter and storage of raw material on pellets quality. In the second part of the project data concerning characteristics of raw material and product quality were collected from two pellet factories: SAABI AB, where spruce is the major raw material, and Bioenergi i Luleaa AB, which uses mainly sawdust from pine. The objectives of this part of the project were to analyse and evaluate the relationship between raw material properties/process parameters and fuel quality using multivariate data analysis. Part three of this project involved a questionnaire survey in which pellets producers were asked at four occasions during one year of production, to give information about variations in raw material properties during various seasons, characteristics of the material during pressing and to supply data related to process parameters. Data concerning variations in pellet quality during the whole year were also requested. The sawdust used in the first part of the project was originated from small diameter trees (14 cm in average) and large diameter stems (30-36 cm) of Scots pine and Norway spruce. One third of the material was dried at room temperature to a moisture content (MC) around 12 % (fresh weight basis), then frozen until needed. The rest of the material was stored in 32 plastic net bags in a large outdoor pile during the period end of May-January. The average dry matter loss in all assortments after eight months of storage was about 0.5 % per month. An attempt to produce pellets from the fresh and stored material from the various

Techno-economic analysis of wood biomass boilers for the greenhouse industry

International Nuclear Information System (INIS)

Chau, J.; Sowlati, T.; Sokhansanj, S.; Preto, F.; Melin, S.; Bi, X.

2009-01-01

The objective of this study is to perform a techno-economic analysis on a typical wood pellet and wood residue boiler for generation of heat to an average-sized greenhouse in British Columbia. The variables analyzed included greenhouse size and structure, boiler efficiency, fuel types, and source of carbon dioxide (CO 2 ) for crop fertilization. The net present value (NPV) show that installing a wood pellet or a wood residue boiler to provide 40% of the annual heat demand is more economical than using a natural gas boiler to provide all the heat at a discount rate of 10%. For an assumed lifespan of 25 years, a wood pellet boiler system could generate NPV of C$259,311 without electrostatic precipitator (ESP) and C$74,695 with ESP, respectively. While, installing a wood residue boiler with or without an ESP could provide NPV of C$919,922 or C$1,104,538, respectively. Using a wood biomass boiler could also eliminate over 3000 tonne CO 2 equivalents of greenhouse gases annually. Wood biomass combustion generates more particulate matters than natural gas combustion. However, an advanced emission control system could significantly reduce particulate matters emission from wood biomass combustion which would bring the particulate emission to a relatively similar level as for natural gas

Wood as a home heating fuel

International Nuclear Information System (INIS)

Wood, K.

1991-01-01

This article describes the development of clean-burning technology in three types of wood-burning appliances: catalytic, non-catalytic, and pellet stoves. A recent study by the Washington State Energy Extension Office concluded that in homes that use both electricity and wood, 73 megawatts of electricity/yr were saved by using wood. Since wood-burning stoves can now meet air quality standards, wood could be considered to be a greenhouse-neutral fuel if more trees are planted as they are consumed

Aiming for market leadership - from electricity utility to pellets manufacturer; Die Marktfuehrerschaft im Visier

Energy Technology Data Exchange (ETDEWEB)

Aeberli, O. E.

2003-07-01

This short article describes the plans of a small Swiss electricity utility to break out of its traditional role in power generation and the distribution of electricity and go into the production of wood pellets. The pellets, which are to be made from waste wood available from a wood processing facility in the utility's own region, are to be produced on a scale which can be described as being quite large for Switzerland. The article discusses this unusual approach for a Swiss power utility, which also operates a wood-fired power station and has diversified into other areas such as electrical house installations and overland power lines. The markets being aimed for are described, including modern low-energy-consumption housing projects.

The case for wood-fuelled heating

International Nuclear Information System (INIS)

Bent, Ewan

2001-01-01

This article looks at the wood heating industry in the UK and examines the heat market and the growth potential in the domestic, public, agricultural and commercial sectors. The current status of wood-fueled heating technology is considered, along with log and chip boilers, and the use of pellet fuel. The economics of wood-fuelled heating, the higher level of utilisation of wood-fuelled heating by utilities in northern European countries compared with the UK, and the barriers to the exploitation of wood fuelled heating are examined

Retrofitting oil fired boilers for pellets based pulverised wood firing at peak load; Konvertering av befintliga oljepannor till pulvereldning foer spetslast

Energy Technology Data Exchange (ETDEWEB)

Malmgren, A.; Tao, L.; Wennstroem, M. [TPS Termiska Processer AB, Nykoeping (Sweden)

2000-03-01

The types of equipment for grinding of pellets used by commercial heat producers today are discussed. Powder from a representative number of plants has been collected and classified using a traditional vibrating sieve and an aerodynamic method 'Aeroklass'. The results show clearly that the difference in 'fluffyness' between a powder produced from pellets, briquettes or directly from wood can be identified by the aerodynamic method. The shapes of different particles are shown in microscope pictures. The requirements of burners and combustion chambers for good burnout of fuel particles are discussed theoretically. Burnout time for wood particles of different size at different temperatures are calculated and the result is presented in diagrams. It is difficult to calculate the residence time for fuel particles in a flame in a generally useful way with any precision. Some diagrams that can be used to approximate the residence time of an aerodynamically small particle, in different parts of a flame, as a function of fuel load and burner diameter are presented. The results of CFD-simulations (with Fluent) of the trajectories of different sized fuel particles in a 20 and a 10 MW flame are shown in 20 pictures. Colour coding is used to show the particle temperature, residence time and combustion stage along the trajectories. The final discussion is based on the analysis of 3 real installations of burners in the size 9 - 20 MW.

Pellet injector research at ORNL

International Nuclear Information System (INIS)

Combs, S.K.; Foster, C.A.; Milora, S.L.

1988-01-01

Advanced plasma fueling systems for magnetic confinement devices are under development a the Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogen isotope pellets at speeds in the range 1-2 km/s and higher. Recently, ORNL provided pneumataic-based pellet fueling systems for two of the world's largest tokamak experiments, the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET). A new versatile centrifuge type injector is being readied at ORNL for use on the Tore Supra tokamak. Also, a new simplified eight-shot injector design has been developed for use on the Princeton Beta Experiment (PBX) and the Advanced Toroidal Facility (ATF). In addition to these confinement physics related activities, ORNL is pursuing advanced technologies to achieve pellet velocities significantly in excess of 2 km/s and is carrying out a Tritium Proof-of-Principle (TPOP) experiment in which the fabrication and acceleration of tritium pellets have already been demonstrated. This paper describes these ongoing activities. 25 refs., 9 figs

Waste-wood-derived fillers for plastics

Science.gov (United States)

Brent English; Craig M. Clemons; Nicole Stark; James P. Schneider

1996-01-01

Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper...

Quality effects caused by torrefaction of pellets made from Scots pine

DEFF Research Database (Denmark)

Shang, Lei; Nielsen, Niels Peter K.; Dahl, Jonas

2012-01-01

by mechanical compression was determined using a material tester and results showed a rapid decrease before torrefaction temperature reached 250°C. Slightly further decrease was observed when increasing the temperature up to 270°C. The strength loss was confirmed by determining the energy required for grinding...... the pellet samples in a bench scale disc mill. Particle size distribution measurements after grinding indicated a significant increase of small particles (diameterca. 2mm). To further analyze the effect on strength, the mechanical durability of pellets was tested according to wood pellet standards, EN 15210...

Controversy. The wood war

International Nuclear Information System (INIS)

James, O.

2010-01-01

The author comments the conflict emerging in France between industries exploiting wood for construction and those exploiting it as a heating material for power generation. The first ones accuse the others to steal their raw material, to pull the prices up, and to destabilize the sector. This conflict takes place notably around sawmill wastes which are used either by wood panel fabricators or by wood pellets producers. Both sectors are claiming they are creating more jobs than the other. The French forest indeed offers good opportunities for both sectors, but other countries which are lacking forest surfaces, are buying wood in France. Several issues are matter of discussion: burning wood seems to go against the reduction of greenhouse gas emissions, subsidies awarded to big heater projects. The situation of the wood sector in Austria, Finland and Poland is briefly presented

Emission of oxygenated polycyclic aromatic hydrocarbons from biomass pellet burning in a modern burner for cooking in China

Science.gov (United States)

Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Wei, Wen; Tao, Shu

2012-12-01

Biomass pellets are undergoing fast deployment widely in the world, including China. To this stage, there were limited studies on the emissions of various organic pollutants from the burning of those pellets. In addition to parent polycyclic aromatic hydrocarbons, oxygenated PAHs (oPAHs) have been received increased concerns. In this study, emission factors of oPAHs (EFoPAHs) were measured for two types of pellets made from corn straw and pine wood, respectively. Two combustion modes with (mode II) and without (mode I) secondary side air supply in a modern pellet burner were investigated. For the purpose of comparison, EFoPAHs for raw fuels combusted in a traditional cooking stove were also measured. EFoPAHs were 348 ± 305 and 396 ± 387 μg kg-1 in the combustion mode II for pine wood and corn straw pellets, respectively. In mode I, measured EFoPAHs were 77.7 ± 49.4 and 189 ± 118 μg kg-1, respectively. EFs in mode II were higher (2-5 times) than those in mode I mainly due to the decreased combustion temperature under more excess air. Compared to EFoPAHs for raw corn straw and pine wood burned in a traditional cooking stove, total EFoPAHs for the pellets in mode I were significantly lower (p pellets burned in mode II was not statistically significant. Taking both the increased thermal efficiencies and decreased EFs into consideration, substantial reduction in oPAH emission can be expected if the biomass pellets can be extensively used by rural residents.

Reductions in emissions of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from combustion of biomass pellets in comparison with raw fuel burning.

Science.gov (United States)

Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Yang, Yifeng; Wang, Wei; Wei, Wen; Wang, Xilong; Liu, Wenxing; Wang, Xuejun; Masse Simonich, Staci L y

2012-06-05

Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW), and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EF(CO), EF(OC), EF(EC), EF(PM), and EF(PAH)) were determined. The average EF(CO), EF(OC), EF(EC), and EF(PM) were 1520 ± 1170, 8.68 ± 11.4, 11.2 ± 8.7, and 188 ± 87 mg/MJ for corn straw pellets and 266 ± 137, 5.74 ± 7.17, 2.02 ± 1.57, and 71.0 ± 54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EF(PAH) for the two pellets were 1.02 ± 0.64 and 0.506 ± 0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EF(OC) and EF(PM) for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EF(CO), EF(OC), EF(EC), and EF(PM) for pellets were significantly lower than those for raw fuels (p 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in traditional cooking stoves with pellets burned in modern pellet burners.

Particle density determination of pellets and briquettes

Energy Technology Data Exchange (ETDEWEB)

Rabier, Fabienne; Temmerman, Michaeel [Centre wallon de Recherches agronomiques, Departement de Genie rural, CRA-W, Chaussee de Namur, 146, B 5030 Gembloux (Belgium); Boehm, Thorsten; Hartmann, Hans [Technologie und Foerderzentrum fuer Nachwachsende Rohstoffe, TFZ, Schulgasse 18, D 94315 Straubing (Germany); Daugbjerg Jensen, Peter [Forest and Landscape, The Royal Veterinary and Agricultural University, Rolighedsvej 23, DK 1958 Frederiksberg C (Denmark); Rathbauer, Josef [Bundesanstalt fuer Landtechnik, BLT, Rottenhauer Strasse,1 A 3250 Wieselburg (Austria); Carrasco, Juan; Fernandez, Miguel [Centro de investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Avenida Complutense, 22 E 28040 Madrid (Spain)

2006-11-15

Several methods and procedures for the determination of particle density of pellets and briquettes were tested and evaluated. Round robin trials were organized involving five European laboratories, which measured the particle densities of 15 pellet and five briquette types. The test included stereometric methods, methods based on liquid displacement (hydrostatic and buoyancy) applying different procedures and one method based on solid displacement. From the results for both pellets and briquettes, it became clear that the application of a method based on either liquid or solid displacement (only tested on pellet samples) leads to an improved reproducibility compared to a stereometric method. For both, pellets and briquettes, the variability of measurements strongly depends on the fuel type itself. For briquettes, the three methods tested based on liquid displacement lead to similar results. A coating of the samples with paraffin did not improve the repeatability and the reproducibility. Determinations with pellets proved to be most reliable when the buoyancy method was applied using a wetting agent to reduce surface tensions without sample coating. This method gave the best values for repeatability and reproducibility, thus less replications are required to reach a given accuracy level. For wood pellets, the method based on solid displacement gave better values of repeatability, however, this instrument was tested at only one laboratory. (author)

Small-scale production and use of wood fuels. Report of the year 2005

International Nuclear Information System (INIS)

Alakangas, E.

2005-01-01

The target areas of the research programme are: Small-scale production and handling of wood fuels, Pellet production, distribution and use, Heating technology and Business and service concepts. Production and processing technology focuses on cost-effectiveness, fuel quality, logistics of production chains and storage, transport and feeding solutions. The quality of pellets in the view of the whole chain: production, storage, distribution and feeding, is under scrutiny. In addition, storage and distribution systems are being developed. The aim is to create functional and comprehensive heat production systems based on the use of wood pellets. Emissions from small-scale use are reduced and efficiency of combustion improved to meet the Central European standard. Modern control, automation and data management systems are applied cost-effectively. The aim is to create comprehensive systems and modular solutions. Business and service concepts relate to all target areas such as heat entrepreneurship and energy service companies (ESCO). The aim is to promote the networking of companies and develop new solutions for fuel and heat production services

The CIT [compact ignition tokamak] pellet injection system: Description and supporting research and development

International Nuclear Information System (INIS)

Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

1989-01-01

The Compact Ignition Tokamak (CIT) will use an advance, high-velocity pellet injection system to achieve and maintain ignited plasmas. Two pellet injectors are provided: a moderate-velocity (1-to 1.5-km/s), single-stage pneumatic injector with high reliability and a high-velocity (4- to 5-km/s), two-stage pellet injector that uses frozen hydrogenic pellets encased in sabots. Both pellet injectors are qualified for operation with tritium feed gas. Issues such as performance, neutron activation of injector components, maintenance, design of the pellet injection vacuum line, gas loads to the reprocessing system, and equipment layout are discussed. Results and plans for supporting research and development (R and D) in the areas of tritium pellet fabrication and high-velocity, repetitive two-stage pneumatic injectors are presented. 7 refs., 4 figs., 2 tabs

ERA-Net Evaluation of technology status for small-scale combustion of pellets from new ash rich biomasses - combustion tests in residential burners

Energy Technology Data Exchange (ETDEWEB)

Roennbaeck, Marie; Johansson, Mathias; Frida Claesson

2008-07-01

In this project, pellets with higher ash content compared to the wood pellets used today on the Swedish market were tested in three domestic-scale burners. The tests were carried out based on EN 303-5. In the flue gas, combustion parameters as carbon monoxide, carbon dioxide, oxygen and hydro carbons were measured, and also more fuel specific parameters such as nitrogen oxides, sulphur dioxide, hydrogen chloride, total dust and particle mass- and number concentration. The dust (fly ash) and bottom ash were characterized chemically. The implications of high ash content on combustion performance are discussed in the report. Altogether five pellets with 8 mm diameter were tested: oilseed straw pellet, reed canary grass pellet (RCG), barley straw pellet, bark pellet and wood pellet. All fuels were dry ranging from 6.5-12 % moisture. The ash content varied from 0.3 weight-% dm in wood to 7.9 % in RCG. Barley straw has a noticeable low ash melting temperature, < 980 deg C, and could not be combusted in any of the burners. The nitrogen content varied nine times and sulphur more than 10 times. The chlorine content was very low in wood and bark and more than 20 times higher in oilseed and barley. The composition of inorganic species in the fuel ash was dominated by calcium, potassium and silica in wood, bark and oilseed pellet, while RCG and barley straw were dominated by silica. The three burners used were commercial and known to fulfil high quality requirements. Burner A is a pellet burner where fuel is supplied on top of the grate with no mechanical mean for moving bottom ash on the grate during combustion. Bottom ash is blown away, and any slag remaining on the grate is removed with a scrape before ignition. Burner B is an upward burning pellet burner where fuel and ash is pushed upwards and the glow bed is exposed to the surrounding combustion department. Burner C is a forward burning grain burner that pushes fuel and ash forwards, inside a cylinder. From the

MINERGIE modules: heat pump - heat pump/solar - wood - wood/solar; Minergie-Module Waermepumpe - Waermepumpe/Solar - Holz - Holz/Solar

Energy Technology Data Exchange (ETDEWEB)

Gallati, J. [Seecon GmbH, Lucerne (Switzerland); Portmann, M. [Buero Markus Portmann, Kriens (Switzerland); Zurfluh, B. [Zurfluh Lottenbach, Lucerne (Switzerland)

2005-07-01

This research report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the feasibility of setting up 'MINERGIE' low-energy-consumption module standards for the production of heat in small residential buildings. The aims of the standards and the basic idea behind the MINERGIE-modules are discussed. The concepts of the modules for heat pumps and wood-fired heating systems and their combination with solar installations are examined, as are their areas of application. The requirements placed on the modules are listed. System concepts, including simple schematics for typical installations, are presented for wood-log, wood-chippings and pellets-fired systems as well as for ground-loop and air-water heat pump systems as well as their solar-aided counterparts. The results of cost-benefit analyses are presented and questions regarding system guarantee and liability are examined.

Superheater fouling in a BFB boiler firing wood-based fuel blends

NARCIS (Netherlands)

Stam, A.F.; Haasnoot, K.; Brem, Gerrit

2014-01-01

Four different fuel blends have been fired in a 28 MWel BFB. Wood pellets (test 0) were not problematic for about ten years, contrary to a mixture of demolition wood, wood cuttings, compost overflow, paper sludge and roadside grass (test 1) which caused excessive fouling at a superheater bundle

Discover the benefits of residential wood heating

International Nuclear Information System (INIS)

2003-01-01

This publication described how residential wood-heating systems are being used to reduce energy costs and increase home comfort. Biomass energy refers to all forms are renewable energy that is derived from plant materials. The source of fuel may include sawmills, woodworking shops, forest operations and farms. The combustion of biomass is also considered to be carbon dioxide neutral, and is not considered to be a major producer of greenhouse gases (GHG) linked to global climate change. Wood burning does, however, release air pollutants, particularly if they are incompletely burned. Incomplete combustion of wood results in dense smoke consisting of toxic gases. Natural Resources Canada helped create new safety standards and the development of the Wood Energy Technical Training Program to ensure that all types of wood-burning appliances are installed correctly and safely to reduce the risk of fire and for effective wood heating. In Canada, more than 3 million families heat with wood as a primary or secondary heating source in homes and cottages. Wood heating offers security from energy price fluctuations and electrical power failures. This paper described the benefits of fireplace inserts that can transform old fireplaces into modern heating systems. It also demonstrated how an add-on wood furnace can be installed next to oil furnaces to convert an oil-only heating system to a wood-oil combination system, thereby saving thousands of dollars in heating costs. Wood pellet stoves are another wood burning option. The fuel for the stoves is produced from dried, finely ground wood waste that is compressed into hard pellets that are loaded into a hopper. The stove can run automatically for up to 24 hours. New high-efficiency advanced fireplaces also offer an alternative heating system that can reduce heating costs while preserving Canada's limited supply of fossil fuels such as oil and gas. 13 figs

Effect of Thermal Storage on the Performance of a Wood Pellet-fired Residential Boiler

Energy Technology Data Exchange (ETDEWEB)

Thomas, Butcher [Brookhaven National Laboratory (BNL), Upton, NY (United States). Sustainable Energy Technologies Dept.

2017-08-31

Interest in the direct use of biomass for thermal applications as a renewable technology is increasing as is also focus on air pollutant emissions from these sources and methods to minimize the impact. This work has focused on wood pellet-fired residential boilers, which are the cleanest fuel in this category. In the residential application the load varies strongly over the course of a year and a high fraction of the load is typically under 15% of the maximum boiler capacity. Thermal storage can be used even with boilers which have modulation capacity typically to 30% of the boiler maximum. One common pellet boiler was tested at full load and also at the minimum load used in the U.S. certification testing (15%). In these tests the load was steady over the test period. Testing was also done with an emulated load profile for a home in Albany, N.Y. on a typical January, March, and April day. In this case the load imposed on the boiler varied hourly under computer control, based on the modeled load for the example case used. The boiler used has a nominal output of 25 kW and a common mixed hardwood/softwood commercial pellet was used. Moisture content was 3.77%. A dilution tunnel approach was used for the measurement of particulate emissions, in accordance with U.S. certification testing requirements. The test results showed that the use of storage strongly reduces cycling rates under part load conditions. The transients which occur as these boilers cycle contribute to increased particulate emissions and reduced efficiency. The time period of a full cycle at a given load condition can be increased by increasing the storage tank volume and/or increasing the control differential range. It was shown that increasing the period strongly increased the measured efficiency and reduced the particulate emission (relative to the no storage case). The impact was most significant at the low load levels. Storage tank heat loss is shown to be a significant factor in thermal efficiency

Emission factors of modern wood-pellet heating units under typical heating conditions - Final report; Emissionsfaktoren moderner Pelletkessel unter typischen Heizbedingungen - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Good, J.; Nussbaumer, T.

2009-12-15

This final report for the Swiss Federal Office of Energy (SFOE) reports on the results of measurements made concerning the emission factors of two modern wood-pellet heating units under typical heating conditions. Using simulations, typical operation in single-family homes and apartment blocks were examined. Emissions during the different phases of operation were examined. Systems with and without buffer storage were also examined. The minimum running times to be striven for are quoted which would lead to a reduction of emissions to an acceptable level. The characteristic operating modes for the two heating units and the results obtained for various emissions are presented and discussed.

Bioenergy Research Programme. Yearbook 1994. Production of wood fuels

International Nuclear Information System (INIS)

Alakangas, E.

1995-01-01

BIOENERGIA Research Programme is one of energy technology programmes of the Finnish Ministry of Trade and Industry (in 1995 TEKES, Technology Development Center). The aim of Bioenergy Research Programme is to increase the use of economically profitable and environmentally sound bioenergy by improving the competitiveness of present peat and wood fuels. Research and development projects will also develop new economically competitive biofuels and new equipment and methods for production, handling and using of biofuels. The funding for 1994 was nearly 50 million FIM and projects numbered 60. The main goal of the production of wood fuels research area is to develop new production methods in order to decrease the production costs to the level of imported fuels. The total potential of the wood fuel use should be at least 1.0 million toe/a (5.5 million m 3 ). There were 27 projects in 1994 for research on wood fuel production. This part of the yearbook 1994 presents the main results of these projects. The wood reserves do not limit the obtainability of the target. Research and development work has, however, directed to development of equipment and research on wood fuels production chains. Many devices, designed for both separate and integrated production of wood fuels became ready or were becoming ready for prototyping, to be used for production tests. Results of the biomass harvesting and properties research were obtained for utilization in 1994. According to the results it is possible to obtain the desired targets both in integrated and separated production of wood fuels. (author)

Wood products research in the USA

Science.gov (United States)

Theodore Wegner

2010-01-01

Forest biomass conversion to biofuels and other value-added co-products; hyper-performance advanced composites custom tailored to end use requirements; advanced high performance wood-based structures; and nanomaterials and nano-enable high performance products from wood represent important research and development investment areas for the successful transformation of...

Opportunities for Pellet Trade - Towards a Single European Pellet Market

International Nuclear Information System (INIS)

Pigaht, Maurice; Janssen, Rainer; Rutz, Dominik; Boehm, Thorsten; Vasen, Norbert; Vegas, Laura; Karapanagiotis, Nicolas

2006-01-01

The potential for Pellets trade in Europe was researched and assessed. Such trade is of key importance for the development of a European pellet market of sufficient supply, demand, price and quality standards. Three target markets were taken as case studies for the trade assessment: Greece, Spain and Italy. All three markets stand to profit greatly from international trade. For these markets, pellet imports could supply the basis for the development of a domestic boiler market. At the same time, pellet exports would allow the planning of larger pellet production plants. Whilst these additional costs amount to some 10-20% of the Pellets price, they are financially acceptable, especially for new markets and 'peaks' in the demand/supply of established markets

Solar thermal energy / exhaust air heat pump / wood pellet furnace for a sustainable heat supply of low energy buildings in older buildings; Solarthermie / Abluft-Waermepumpe / Pelletofen. Kombisysteme zur nachhaltigen Waermeversorgung von Niedrigenergiehaeusern im Gebaeudebestand

Energy Technology Data Exchange (ETDEWEB)

Diefenbach, Nikolaus; Born, Rolf [Institut Wohnen und Umwelt GmbH, Darmstadt (Germany); Staerz, Norbert [Ingenieurbuero inPlan, Pfungstadt (Germany)

2009-11-13

The research project under consideration reports on combination systems for a sustainable heat supply for low-energy buildings in older building. For this, a central and decentralized system configuration consisting of solar thermal energy, exhaust air heat pump and wood pellet furnace are presented. Solutions for an interaction of these three heat suppliers in one plant are designated regarding the control strategy. The fundamentals of the computerized simulations for the central and decentralized system are presented. A cost estimate with both variants of the combination system as well as a comparison with conventional energy-saving heat supply systems follow.

Wood energy x 2 - Scenario for the development of wood energy use in Switzerland

International Nuclear Information System (INIS)

2004-01-01

This study for the Swiss Agency for the Environment, Forests and Landscapes (SAEFL) and the Swiss wood-energy association (Holzenergie Schweiz) presents the results of a scenario-study that examined if, and under what conditions, doubling the use of wood energy in Switzerland could help reach carbon dioxide reduction targets. Two scenarios are presented that are based on high and low rates of growth for the number of automatic wood-chipping or pellets-fired installations. For both scenarios, figures are presented on the amount of wood used and the heating energy generated. The political and financial prerequisites for the scenarios are discussed and other boundary conditions are defined. The report draws conclusions from the study of the two scenarios and summarises the political action deemed necessary

HYGROSCOPICITY OF WOOD PLASTIC COMPOSITES MADE WITH PADOU FLOUR AND POLYPROPYLENE PELLETS

OpenAIRE

Moise Emmanuel NZUDJOM SOUOP; Joseph Albert MUKAM FOTSING

2012-01-01

The manufacture of objects in wood-plastic composites which is a material already available in many developed countries seems almost unknown in Cameroon since the production factory of objects in wood-plastic composites does not exist up till here. Interested in the study of properties of wood-plastic composites throughconnection of simple plastic and wood, we have oriented our paper in the elaboration, realization and physical characterization of wood-plastic composites with Padou and polypr...

PELLETS AND PELLETIZATION: EMERGING TRENDS IN THE PHARMA INDUSTRY.

Science.gov (United States)

Zaman, Muhammad; Saeed-Ul-Hassan, Syed; Sarfraz, Rai Muhammad; Batool, Nighat; Qureshi, Muhammad Junaid; Akram, Muhammad Abdullah; Munir, Saiqa; Danish, Zeeshan

2016-11-01

The present time is considered as an era of advancements in drug delivery systems. Different novel approaches are under investigation that range from uniparticulate to multi particulate system, macro to micro and nano particulate systems. Pelletization is one of the novel drug delivery technique that provides an effective way to deliver the drug in modified pattern. It is advantageous in providing site specific delivery of the drug. Drugs with unpleasant taste, poor bioavailability and short biological half-life can be delivered efficiently through pellets. Their reduced size makes them more valuable as compared to the conventional drug deliv- ery system. Different techniques are used to fabricate the pellets such as extrusion and spheronization, hot melt extrusion, powder layering, suspension or solution layering, freeze pelletization and pelletization by direct compression method. Various natural polymers including xanthan gum, guar gum, tragacanth and gum acacia, semisynthetic polymers like cellulose derivatives, synthetic polymers like derivatives of acrylamides, can be used in pellets formulation. Information provided in this review is collected from various national and intemational research articles, review articles and literature available in the books. The purpose of the current review is to discuss pellets, their characterizations, different techniques of pelletization and the polymers with potential of being suitable for pellets formulation.

Western Canadian wood residue production and consumption trends

International Nuclear Information System (INIS)

McCloy, B.

2006-01-01

This presentation considered various trends in western Canadian wood residue production and consumption. Potential markets for wood residue products were also discussed. Trends were reviewed by province for the years 2000-2004. British Columbia (BC) is currently the largest producer of residue in the country, and also retains the largest surpluses of bark, sawdust and shavings. Wood residues in BC are used in pulp and plywood mill production, as well as in the creation of particleboard and MDF. Surplus mill wood residue production in the province has greatly increased due to the Mountain Pine Beetle (MPB) infestation, which has in turn spurred expansion of the BC interior sawmill industry. The infestation has also resulted in a glut of pulp chips. Current wood residue products in Alberta are mostly used in pulp mill combined heat and power (CHP) systems, as well as for wood pellet production and the creation of particleboard and MDF. It was noted that surplus residues are rapidly declining in the province. Saskatchewan's wood residue storage piles are estimated to contain 2,900,000 BDt, while Manitoba surpluses are relatively minor. It was suggested that high natural gas prices have increased the payback on wood energy systems to approximately 2 years. The value of wood residue is now greater than $100/BDt as a substitute for natural gas once the wood energy system has been fully depreciated. Sawmills may now wish to consider equipping themselves to sell wood residue products, as most sawmills only require 20 per cent of their residues for heating purposes. It was concluded that markets for hog fuel wood pellets should be developed in Canada and internationally. Future markets may also develop if natural gas currently used in pulp mill power boilers and lime kilns is replaced with wood residue energy systems. refs., tabs., figs

Combustion Aerosols from Full-Scale Suspension-Firing of Wood Pellets

DEFF Research Database (Denmark)

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

2012-01-01

The objectives of the present work were to investigate the aerosol formation mechanisms during full-scale suspension firing of wood, and, to evaluate the effect of coal fly ash addition on the formation of aerosols under different ash load conditions. Tests with suspension firing of 100 % wood...

Pelleted biochar: chemical and physical properties show potential use as a substrate in container nurseries

Science.gov (United States)

R. Kasten Dumroese; Juha Heiskanen; Karl Englund; Arja Tervahauta

2011-01-01

We found that peat moss, amended with various ratios of pellets comprised of equal proportions of biochar and wood flour, generally had chemical and physical properties suitable for service as a substrate during nursery production of plants. High ratios of pellets to peat (>50%) may be less desirable because of high C:N, high bulk density, swelling associated with...

Characterisation of wood combustion ashes

DEFF Research Database (Denmark)

Maresca, Alberto

The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...... for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition...

Analysis of existing structure and emissions of wood combustion plants for the production of heat and electricity in Bavaria

International Nuclear Information System (INIS)

Joa, Bettina

2014-01-01

This work deals with the detailed analysis of the existing structure of all Bavarian wood burning plants for the generation of heat and electricity as well as the determination of the resulting emission emissions in 2013. The number of wood burning plants in the single-chamber fireplaces, wood central heating and wood-fired heating plants which are in operation in the year 2013 were determined, and how many plants are existing in the various areas like pellet stoves, traditional ovens, wood-burning fireplace, pellet central heating systems, wood chips central heating systems, fire-wood central heating systems, wood combined heat and power plant (electricity and heat) and wood power plants (heat). In addition, the regional distribution of the wood burning plants in the Bavarian governmental districts is investigated as well as the type and amount of energy produced by them (heat, electricity). [de

Analysis of environmental and economic aspects of international pellet supply chains

Energy Technology Data Exchange (ETDEWEB)

Ehrig, Rita

2014-01-17

Biomass plays a key role to achieve the EU's 20-20-20 energy and climate targets. Because of rising European demand and limited domestic resources, the EU relies on worldwide imports. Given this framework, the present thesis explores the influences on wood pellet supply chains considering different environmental policies, price risks and the effect of torrefaction pretreatment. The examinations refer to three real case studies for pellet trade from Australia, Canada, and Russia to Europe. In the first investigation, the efficiency of co-firing imported wood pellets in terms of CO{sub 2} savings and related subsidy schemes is analysed. Scenarios show that co-firing biomass is efficient to contribute to the EU energy targets. Though, policy makers could use these instruments more effective when directing sourcing decision towards options with even less environmental impacts. The second analysis explores the influence of statistically derived price risks on total supply chain economics. It is shown that price risks can effect strong fluctuations in the short term, which seriously affect the profitability of individual trade routes. Securing the supply chain is mainly based on individual producer-buyer agreements, personal branch experiences and fast reactions on the subsidy system. Systematic evaluation of supply chains could contribute to a more reliable market and thus foster investment decisions. In the last investigation, the economic and environmental performance of potential torrefaction-based supply chains is assessed. As a result, torrefaction-based supply chains turn out to be a certain alternative to conventional ones. Though, still huge research efforts and industrial demonstration are required to make torrefied biomass a real alternative on the market.

Analysis of environmental and economic aspects of international pellet supply chains

International Nuclear Information System (INIS)

Ehrig, Rita

2014-01-01

Biomass plays a key role to achieve the EU's 20-20-20 energy and climate targets. Because of rising European demand and limited domestic resources, the EU relies on worldwide imports. Given this framework, the present thesis explores the influences on wood pellet supply chains considering different environmental policies, price risks and the effect of torrefaction pretreatment. The examinations refer to three real case studies for pellet trade from Australia, Canada, and Russia to Europe. In the first investigation, the efficiency of co-firing imported wood pellets in terms of CO 2 savings and related subsidy schemes is analysed. Scenarios show that co-firing biomass is efficient to contribute to the EU energy targets. Though, policy makers could use these instruments more effective when directing sourcing decision towards options with even less environmental impacts. The second analysis explores the influence of statistically derived price risks on total supply chain economics. It is shown that price risks can effect strong fluctuations in the short term, which seriously affect the profitability of individual trade routes. Securing the supply chain is mainly based on individual producer-buyer agreements, personal branch experiences and fast reactions on the subsidy system. Systematic evaluation of supply chains could contribute to a more reliable market and thus foster investment decisions. In the last investigation, the economic and environmental performance of potential torrefaction-based supply chains is assessed. As a result, torrefaction-based supply chains turn out to be a certain alternative to conventional ones. Though, still huge research efforts and industrial demonstration are required to make torrefied biomass a real alternative on the market.

Time-resolved characterization of primary emissions from residential wood combustion appliances.

Science.gov (United States)

Heringa, M F; DeCarlo, P F; Chirico, R; Lauber, A; Doberer, A; Good, J; Nussbaumer, T; Keller, A; Burtscher, H; Richard, A; Miljevic, B; Prevot, A S H; Baltensperger, U

2012-10-16

Primary emissions from a log wood burner and a pellet boiler were characterized by online measurements of the organic aerosol (OA) using a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and of black carbon (BC). The OA and BC concentrations measured during the burning cycle of the log wood burner, batch wise fueled with wood logs, were highly variable and generally dominated by BC. The emissions of the pellet burner had, besides inorganic material, a high fraction of OA and a minor contribution of BC. However, during artificially induced poor burning BC was the dominating species with ∼80% of the measured mass. The elemental O:C ratio of the OA was generally found in the range of 0.2-0.5 during the startup phase or after reloading of the log wood burner. During the burnout or smoldering phase, O:C ratios increased up to 1.6-1.7, which is similar to the ratios found for the pellet boiler during stable burning conditions and higher than the O:C ratios observed for highly aged ambient OA. The organic emissions of both burners have a very similar H:C ratio at a given O:C ratio and therefore fall on the same line in the Van Krevelen diagram.

NIR Techniques Create Added Values for the Pellet and Biofuel Industry

Energy Technology Data Exchange (ETDEWEB)

Lestander, Torbjoern A. [Swedish Univ of Agricultural Science, Umeaa (Sweden). Unit of Biomass Technology and Chemistry; Johnsson, Bo; Grothage, Morgan [Casco Adhesives AB, Sundsvall (Sweden)

2006-07-15

Pelletizing of biomass as biofuels increases energy density, improves storability and reduces transport costs. This process is a major key factor in the transition from fossil fuels to renewable biomass refined as solid biofuels. The fast growing pellet industry is today producing more than 1.2 Gg wood Pellets in Sweden - one of the leading nations to utilize bioenergy in its energy mix. The multitude of raw biomaterials available for fuel pellet production and their widely different characteristics stress the need for rapid characterization methods. A suitable technique for characterization of variation in biomaterials is near infrared (NIR) spectrometry. NIR radiation interacts with polar molecules and especially with structural groups O-H as in water, C-H as in biomass, but also with C-O bonds and C=C double bonds frequently found in biomass. Biomass contains mostly the atoms C, O and H. This means that transmittance or reflectance in the NIR wavelength region covers most of the covalent bonds in biomass, except for the C-C bonds in carbon chains. The NIR technique is also developed for on-line measurement in harsh industrial conditions. Thus, NIR techniques can be applied for on-line and real time characterization of raw biomass as well as in the refinement process of biomass into standardized solid biofuels. Spectral patterns in the NIR region contain chemical and physical information structure that together with reference parameters can be modeled by multivariate calibration methods to obtain predictions. These predictions can be presented to the operators in real time on screens as charts based on multivariate statistical process controls. This improves the possibilities to overview the raw biomass variation and to control the responses of the treatments the biomass undergo in the pelletizing process. The NIR-technique is exemplified by a 23-factorial experiment that was carried out in a pellet plant using sawdust as raw material to produce wood Pellets as

Solutions for wood-based bio-energy price discovery

Energy Technology Data Exchange (ETDEWEB)

Teraes, Timo [FOEX Indexes Ltd., Helsinki (Finland)], e-mail: timo@foex.fi

2012-11-01

Energy prices are highly volatile. This volatility can have serious ill-effects on the profitability of companies engaged in the energy business. There are, however, a number of price risk management tools which can be used to reduce the problems caused by price volatility. International trade of wood pellets and wood chips is rapidly growing. A good price transparency helps in developing the trade further. In order to meet the renewable energy targets within the EU, further growth of volumes is needed, at least within Europe and from overseas supply sources to the European markets. Reliable price indices are a central element in price risk management and in general price discovery. Exchanges have provided, in the past, the most widely known price discovery systems. Since 1990's, an increasing number of price risk management tools has been based on cash settlement concept. Cash settlement requires high quality benchmark price indices. These have been developed by the exchanges themselves, by trade press and by independent price benchmark provider companies. The best known of these benchmarks in forest industry and now also in wood-based bioenergy products are the PIX indices, provided by FOEX Indexes Ltd. This presentation discusses the key requirements for a good price index and the different ways of using the indices. Price relationships between wood chip prices and pellet prices are also discussed as will be the outlook for the future volume growth and trade flows in woodchips and pellets mainly from the European perspective.

Short Communication: Emission of Oxygenated Polycyclic Aromatic Hydrocarbons from Biomass Pellet Burning in a Modern Burner for Cooking in China.

Science.gov (United States)

Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Wei, Wen; Tao, Shu

2012-12-01

Biomass pellets are undergoing fast deployment widely in the world, including China. To this stage, there were limited studies on the emissions of various organic pollutants from the burning of those pellets. In addition to parent polycyclic aromatic hydrocarbons, oxygenated PAHs (oPAHs) have been received increased concerns. In this study, emission factors of oPAHs (EF oPAHs ) were measured for two types of pellets made from corn straw and pine wood, respectively. Two combustion modes with (mode II) and without (mode I) secondary side air supply in a modern pellet burner were investigated. For the purpose of comparison, EF oPAHs for raw fuels combusted in a traditional cooking stove were also measured. EF oPAHs were 348±305 and 396±387 µg/kg in the combustion mode II for pine wood and corn straw pellets, respectively. In mode I, measured EF oPAHs were 77.7±49.4 and 189±118 µg/kg, respectively. EFs in mode II were higher (2-5 times) than those in mode I mainly due to the decreased combustion temperature under more excess air. Compared to EF oPAHs for raw corn straw and pine wood burned in a traditional cooking stove, total EF oPAHs for the pellets in mode I were significantly lower ( p < 0.05 ), likely due to increased combustion efficiencies and change in fuel properties. However, the difference between raw biomass fuels and the pellets burned in mode II was not statistically significant. Taking both the increased thermal efficiencies and decreased EFs into consideration, substantial reduction in oPAH emission can be expected if the biomass pellets can be extensively used by rural residents.

Time-resolved analysis of primary volatile emissions and secondary aerosol formation potential from a small-scale pellet boiler

Science.gov (United States)

Czech, Hendryk; Pieber, Simone M.; Tiitta, Petri; Sippula, Olli; Kortelainen, Miika; Lamberg, Heikki; Grigonyte, Julija; Streibel, Thorsten; Prévôt, André S. H.; Jokiniemi, Jorma; Zimmermann, Ralf

2017-06-01

Small-scale pellet boilers and stoves became popular as a wood combustion appliance for domestic heating in Europe, North America and Asia due to economic and environmental aspects. Therefore, an increasing contribution of pellet boilers to air pollution is expected despite their general high combustion efficiency. As emissions of primary organic aerosol (POA) and permanent gases of pellet boilers are well investigated, the scope of this study was to investigate the volatile organic emissions and the formation potential of secondary aerosols for this type of appliance. Fresh and aged emissions were analysed by a soot-particle aerosol time-of-flight mass spectrometry (SP-AMS) and the molecular composition of the volatile precursors with single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) at different pellet boiler operation conditions. Organic emissions in the gas phase were dominated by unsaturated hydrocarbons while wood-specific VOCs, e.g. phenolic species or substituted furans, were only detected during the starting phase. Furthermore, organic emissions in the gas phase were found to correlate with fuel grade and combustion technology in terms of secondary air supply. Secondary organic aerosols of optimised pellet boiler conditions (OPT, state-of-the-art combustion appliance) and reduced secondary air supply (RSA, used as a proxy for pellet boilers of older type) were studied by simulating atmospheric ageing in a Potential Aerosol Mass (PAM) flow reactor. Different increases in OA mass (55% for OPT, 102% for RSA), associated with higher average carbon oxidation state and O:C, could be observed in a PAM chamber experiment. Finally, it was found that derived SOA yields and emission factors were distinctly lower than reported for log wood stoves.

Portuguese pellets market: Analysis of the production and utilization constrains

International Nuclear Information System (INIS)

Monteiro, Eliseu; Mantha, Vishveshwar; Rouboa, Abel

2012-01-01

As opposite in Portugal, the wood pellets market is booming in Europe. In this work, possible reasons for this market behavior are foreseen according to the key indicators of biomass availability, costs and legal framework. Two major constrains are found in the Portuguese pellets market: the first one is the lack of an internal consumption, being the market based on exportations. The second one is the shortage of raw material mainly due to the competition with the biomass power plants. Therefore, the combination of the biomass power plants with pellet production plants seems to be the best option for the pellets production in the actual Portuguese scenario. The main constrains for pellets market has been to convince small-scale customers that pellets are a good alternative fuel, mainly due to the investment needed and the strong competition with natural gas. Besides some benefits in the acquisition of new equipment for renewable energy, they are insufficient to cover the huge discrepancy of the investment in pellets heating. However, pellets are already economic interesting for large utilizations. In order cover a large amount of households, additional public support is needed to cover the supplementary costs of the pellets heating systems. - Highlights: ► There is a lack of internal consumption being the pellets market based on exportation. ► The shortage of raw material is mainly due to the biomass power plants. ► Combining pellet plants with biomass power plants seems to be a wise solution. ► The tax benefits of renewable energy equipments are not enough to cover the higher investment. ► Pellets are already economic interesting for large utilizations in the Portuguese scenario.

Thermal Properties of Wood-Plastic Composites Prepared from Hemicellulose-extracted Wood Flour

Directory of Open Access Journals (Sweden)

A.A. Enayati

2013-01-01

Full Text Available Hemicellulose of Southern Yellow Pine wood spices was extracted by pressurized hot water at three different temperatures: 140°C, 155°C and 170°C. Compounding with PP (polypropylene was performed by extrusion after preparing wood flour and sieving to determine its mesh size. The ratio of wood to polymer was 50:50 based on oven-dry weight of wood flour. All extraction treatments and control samples were compounded under two sets of conditions, without and with 2% MAPP as coupling agent. Injection molding was used to make tensile test samples (dogbone from the pellets made by extrusion. Thermal properties of wood-plastic composites were studied by TGA and DSC while the thermal stability of pretreated wood flours, PP and MAPP were studied by TGA as well. The greater weight loss of wood materials was an indication that higher treatment temperature increases the extractability of hemicellulose. The removal of hemicellulose by extraction improves thermal stability of wood flour, especially for extraction at 170°C. Wood-plastic composites made from extracted fibers at 170°C showed the highest thermal stability. Coupling agent did not have a significant effect on thermal stability but it improved the degree of crystallinity of the composites.Surface roughness of wood fiber increased after treatment. Extraction of hemicellulose increased the degree of crystallinity but it was not significant except for samples from treated wood flour at 170°C and with MAPP.

A proposal for pellet production from residual woody biomass in the island of Majorca (Spain

Directory of Open Access Journals (Sweden)

Javier Sánchez

2015-09-01

Full Text Available The use of residual biomass for energy purposes is of great interest in isolated areas like Majorca for waste reduction, energy sufficiency and renewable energies development. In addition, densification processes lead to easy-to-automate solid biofuels which additionally have higher energy density. The present study aims at (i the estimation of the potential of residual biomass from woody crops as well as from agri-food and wood industries in Majorca, and (ii the analysis of the optimal location of potential pellet plants by means of a GIS approach (location-allocation analysis and a cost evaluation of the pellets production chain. The residual biomass potential from woody crops in Majorca Island was estimated at 35,874 metric tons dry matter (t DM per year, while the wood and agri-food industries produced annually 21,494 t DM and 2717 t DM, respectively. Thus, there would be enough resource available for the installation of 10 pellet plants of 6400 t·year−1 capacity. These plants were optimally located throughout the island of Mallorca with a maximum threshold distance of 28 km for biomass transport from the production points. Values found for the biomass cost at the pellet plant ranged between 57.1 €·t−1 and 63.4 €·t−1 for biomass transport distance of 10 and 28 km. The cost of pelleting amounted to 56.7 €·t−1; adding the concepts of business fee, pellet transport and profit margin (15%, the total cost of pelleting was estimated at 116.6 €·t−1. The present study provides a proposal for pellet production from residual woody biomass that would supply up to 2.8% of the primary energy consumed by the domestic and services sector in the Balearic Islands.

Progress in researches on MOX fuel pellet producing technology in China

International Nuclear Information System (INIS)

Hu Xiaodan

2010-01-01

Being the key section of nuclear-fuel cycle, the producing technology of MOX(UO 2 -PuO 2 ) fuel had driven to maturity in France, England, Russia, Belgium, etc. MOX fuel had been applied in FBR and LWR successfully in those countries. With the rapidly developing of nuclear-generated power, the MOX fuel for FBR and LWR was active demanded in China. However, the producing technology of MOX fuel developed slowly. During the period of 'the seventh five year's project', MOX fuel pellet was produced by mechanically mixed method and oxalate deposited method, respectively. Parts of cool performance of MOX fuel pellet produced by oxalate deposited method reached the qualification of fuel for FBR. During the period of 'the ninth five year's project' and 'the tenth five year's project', the technical route of producing MOX fuel was determined, and the test line of producing MOX fuel was built preliminarily. In the same time, the producing technology and analyzing technology of MOX fuel pellet by mechanically mixed was studied roundly, and the representative analogue pellet(UO 2 -CeO 2 ) was produced. That settled the supporting technology for the commercial process and research of MOX fuel rod and MOX fuel module. (authors)

Wood fuel price survey for 2008 and 2009. Synthesis

International Nuclear Information System (INIS)

2010-01-01

Based on interviews on telephone with wood fuel vendors and wholesalers, pellet producers, local community boiler managers, and individuals, this study, while giving several data figures and tables, proposes a price analysis for the housing sector (price evolution for individuals for different kinds and sizes of fuel woods), a comparison with other fuels and energies (electricity, gas) whether wood is used as the primary or secondary heating mean. It also comments the price scattering. It proposes the same kind of analysis for local communities

Chemical composition and speciation of particulate organic matter from modern residential small-scale wood combustion appliances.

Science.gov (United States)

Czech, Hendryk; Miersch, Toni; Orasche, Jürgen; Abbaszade, Gülcin; Sippula, Olli; Tissari, Jarkko; Michalke, Bernhard; Schnelle-Kreis, Jürgen; Streibel, Thorsten; Jokiniemi, Jorma; Zimmermann, Ralf

2018-01-15

Combustion technologies of small-scale wood combustion appliances are continuously developed decrease emissions of various pollutants and increase energy conversion. One strategy to reduce emissions is the implementation of air staging technology in secondary air supply, which became an established technique for modern wood combustion appliances. On that account, emissions from a modern masonry heater fuelled with three types of common logwood (beech, birch and spruce) and a modern pellet boiler fuelled with commercial softwood pellets were investigated, which refer to representative combustion appliances in northern Europe In particular, emphasis was put on the organic constituents of PM2.5, including polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs) and phenolic species, by targeted and non-targeted mass spectrometric analysis techniques. Compared to conventional wood stoves and pellet boilers, organic emissions from the modern appliances were reduced by at least one order of magnitude, but to a different extent for single species. Hence, characteristic ratios of emission constituents and emission profiles for wood combustion identification and speciation do not hold for this type of advanced combustion technology. Additionally, an overall substantial reduction of typical wood combustion markers, such as phenolic species and anhydrous sugars, were observed. Finally, it was found that slow ignition of log woods changes the distribution of characteristic resin acids and phytosterols as well as their thermal alteration products, which are used as markers for specific wood types. Our results should be considered for wood combustion identification in positive matrix factorisation or chemical mass balance in northern Europe. Copyright © 2017 Elsevier B.V. All rights reserved.

Wood energy markets, 2010-2011

Science.gov (United States)

Francisco Aguilar; Christopher Gaston; Rens Hartkamp; Warren Mabee; Kenneth Skog

2011-01-01

Global wood energy markets continue to grow, driven primarily by demand in the EU and its commitment to meet 20% of energy consumption from renewable sources by 2020. Large investments in industrial pellet-production capacity have been made under expectations of a continuously growing demand, mainly from the EU. Concern about how energy and climate-change policies may...

The influence of design and fuel parameters on the particle emissions from wood pellets combustion. Final report

Energy Technology Data Exchange (ETDEWEB)

Wiinikka, Henrik; Gebart, Rikard [Energy Technology Centre, Piteaa (Sweden)

2005-02-01

Combustion of solid biomass under fixed bed conditions is a common technique to generate heat and power in both small and large scale grate furnaces (domestic boilers, stoves, district heating plants). Unfortunately, combustion of biomass will generate particle emissions containing both large fly ash particles and fine particles that consist of fly ash and soot. The large fly ash particles have been produced from fusion of non-volatile ash-forming species in burning char particle. The inorganic fine particles have been produced from nucleation of volatilised ash elements (K, Na, S, Cl and Zn). If the combustion is incomplete, soot particles are also produced from secondary reaction of tar. The particles in the fine fraction grows by coagulation and coalescence to a particle diameter around 0.1 pm. Since the smallest particles are very hard to collect in ordinary cleaning devices they contribute to the ambient air pollution. Furthermore, fine airborne particles have been correlated to adverse effects on the human health. It is therefore essential to minimize particle formation from the combustion process and thereby reduce the emissions of particulates to the ambient air. The aim with this project is to study particle emissions from small scale combustion of wood pellets and to investigate the impact of different operating, construction and fuel parameters on the amount and characteristic of the combustion generated particles. To address these issues, experiments were carried out in a 10 kW updraft fired wood pellets reactor that has been custom designed for systematic investigations of particle emissions. In the flue gas stack, particle emissions were sampled on a filter. The particle mass and number size distributions were analysed by a low pressure cascade impactor and a SMPS (Scanning Electron Mobility Particle Sizer). The results showed that the temperature and the flow pattern in the combustion zone affect the particle emissions. Increasing combustion

Effect of temperature during wood torrefaction on the formation of lignin liquid intermediates

Science.gov (United States)

Manuel Raul Pelaez-Samaniego; Vikram Yadama; Manuel Garcia-Perez; Eini Lowell; Armando G. McDonald

2014-01-01

Torrefaction enhances physical properties of lignocellulosic biomass and improves its grindability. Energy densification, via fuel pellets production, is one of the most promising uses of torrefaction. Lignin contributes to self-bonding of wood particles during pelletization. In biomass thermal pretreatment, part oflignin (in the form of lignin liquid intermediates –...

Environmental assessment of wood domestic heating. Synthetic report

International Nuclear Information System (INIS)

2005-12-01

This report proposes a synthesis of the results of an environmental assessment of wood domestic heating. This study is based on a life cycle analysis which quantifies the impacts on the environment of all the related activities: fuel extraction, retailing, final use, and so on. Environmental impacts are assessed by means of different indicators: energetic assessment, greenhouse effect assessment, air pollution (acidification), water pollution (eutrophication), toxic material emissions in air and into the soils. Wood is compared to other heating sources (gas, fuel, electricity). Ways to improve this environmental assessment are discussed for the different types of wood (logs, pellets)

Fire and fire extinguishment in silos. An experimental study[Storage of wood fuel pellets]; Brand och brandslaeckning i siloanlaeggningar. En experimentell studie

Energy Technology Data Exchange (ETDEWEB)

Persson, Henry; Blomqvist, Per; Zhenghua Yan

2007-01-15

A series of four tests have been conducted with wood pellets stored in a reduced size silo. The tests were conducted in order to increase the knowledge on fire development, detection and extinction technique in silo fires. The project originated from a pre-study on the extinction of silo fires made for the Swedish Rescue Service Agency (SRV). The test silo was built of concrete rings, had a diameter of 1 m, and a height of almost 6 m, which gave a volume of 4.4 m{sup 3}. The silo was filled with wood pellets up to a height of 5 m. A local auto ignition was imitated by a coiled heating wire placed in the pellet bulk centrally in the silo and a self sustaining pyrolysis zone was established within one hour. The silo was instrumented with almost 100 thermocouples as a mean to follow the development of the pyrolysis zone and later the efficiency of the extinguishment. Gas analyses were further made, both in the top of the silo, and at four different levels in the pellet bulk. After 30 hours the extinguishment was initiated using nitrogen (N{sub 2}) and carbon dioxide (CO{sub 2}), respectively. The gas was injected into the bottom of the silo. Two tests were also conducted where gas injection was combined foam application in the top of the silo. The tests showed that the pyrolysis zone preferably spreads downwards in the silo, while moisture and pyrolysis gases form a wave that slowly spreads upwards. It was difficult to detect the fire before the main 'gas wave' reached the pellet surface in the silo top, and detection time was about 20 hours in these tests. The spread of the pyrolysis zone, downward, was even slower. The slow development is probably an explanation of why real silo fires often are rather extensive once discovered. Inerting the silo with either nitrogen or carbon dioxide worked out well in the tests. The gas must be in gas phase and slowly introduced into the silo, as close to the bottom as possible. An efficient extinction implies an air

Regional prices in the Swedish wood-fuel market

International Nuclear Information System (INIS)

Hillring, Bengt

1999-01-01

This paper analyses, through a statistical survey, the regional distribution of prices on the commercial wood-fuel market for district heating plants and the pellets market for single family houses. The existing market watch of the national Swedish wood-fuel market has been developed for both refined and unrefined wood-fuels. The last five years the trend for wood-fuel prices on the district heating market has been stable, with a slight increase in the price of refined wood-fuels. However, on the young and fast-growing household market for pellets, prices have increased 12% during the last three years. The distribution of prices for northern, middle and southern Sweden indicates differences within 5% between the regions. The limited price difference between Swedish regions are a product of a large domestic supply and an increasing trade among regions in Europe, putting pressure on prices. Regional differences, mirrored as transportation distances and local production costs are key factors that could explain this regional price variation. However, the development of a commercial market with less regulation tends to level out prices. Consumers on the household market purchase small quantities and do not have the same possibility as district heating companies to take advantage of the oversupply opportunity and thus face a faster price development. The weaker market position of the consumers also tends to give homogeneous prices between regions of the residential sector. (Author)

Handbook for Small-Scale Densified Biomass Fuel (Pellets) Manufacturing for Local Markets.

Energy Technology Data Exchange (ETDEWEB)

Folk, Richard L.; Govett, Robert L.

1992-07-01

Wood pellet manufacturing in the Intermountain West is a recently founded and rapidly expanding energy industry for small-scale producers. Within a three-year period, the total number of manufacturers in the region has increased from seven to twelve (Folk et al., 1988). Small-scale industry development is evolving because a supply of raw materials from small and some medium-sized primary and secondary wood processors that has been largely unused. For the residue producer considering pellet fuel manufacturing, the wastewood generated from primary products often carries a cost associated with residue disposal when methods at-e stockpiling, landfilling or incinerating. Regional processors use these methods for a variety of reasons, including the relatively small amounts of residue produced, residue form, mixed residue types, high transportation costs and lack of a local market, convenience and absence of regulation. Direct costs associated with residue disposal include the expenses required to own and operate residue handling equipment, costs for operating and maintaining a combustor and tipping fees charged to accept wood waste at public landfills. Economic and social costs related to environmental concerns may also be incurred to include local air and water quality degradation from open-air combustion and leachate movement into streams and drinking water.

Antioxidant airway responses following experimental exposure to wood smoke in man

Directory of Open Access Journals (Sweden)

Sehlstedt Maria

2010-08-01

Full Text Available Abstract Background Biomass combustion contributes to the production of ambient particulate matter (PM in rural environments as well as urban settings, but relatively little is known about the health effects of these emissions. The aim of this study was therefore to characterize airway responses in humans exposed to wood smoke PM under controlled conditions. Nineteen healthy volunteers were exposed to both wood smoke, at a particulate matter (PM2.5 concentration of 224 ± 22 μg/m3, and filtered air for three hours with intermittent exercise. The wood smoke was generated employing an experimental set-up with an adjustable wood pellet boiler system under incomplete combustion. Symptoms, lung function, and exhaled NO were measured over exposures, with bronchoscopy performed 24 h post-exposure for characterisation of airway inflammatory and antioxidant responses in airway lavages. Results Glutathione (GSH concentrations were enhanced in bronchoalveolar lavage (BAL after wood smoke exposure vs. air (p = 0.025, together with an increase in upper airway symptoms. Neither lung function, exhaled NO nor systemic nor airway inflammatory parameters in BAL and bronchial mucosal biopsies were significantly affected. Conclusions Exposure of healthy subjects to wood smoke, derived from an experimental wood pellet boiler operating under incomplete combustion conditions with PM emissions dominated by organic matter, caused an increase in mucosal symptoms and GSH in the alveolar respiratory tract lining fluids but no acute airway inflammatory responses. We contend that this response reflects a mobilisation of GSH to the air-lung interface, consistent with a protective adaptation to the investigated wood smoke exposure.

Carbon savings with transatlantic trade in pellets: accounting for market-driven effects

International Nuclear Information System (INIS)

Wang, Weiwei; Khanna, Madhu; Dwivedi, Puneet; Abt, Robert

2015-01-01

Exports of pellets from the United States (US) are growing significantly to meet the demand for renewable energy in the European Union. This transatlantic trade in pellets has raised questions about the greenhouse gas (GHG) intensity of these pellets and their effects on conventional forest product markets in the US. This paper examines the GHG intensity of pellets exported from the US using either forest biomass only or forest and agricultural biomass combined. We develop an integrated dynamic, price-endogenous, partial equilibrium model of the forestry, agricultural, and transportation sectors in the US to investigate not only the direct life-cycle GHG intensity of pellets but also the accompanying indirect market and land use effects induced by changes in prices of forest and agricultural products over the 2007–2032 period. Across different scenarios of high and low pellet demand that can be met with either forest biomass only or with forest and agricultural biomass, we find that the GHG intensity of pellet based electricity is 74% to 85% lower than that of coal-based electricity. We also find that the GHG intensity of pellets produced using agricultural and forest biomass is 28% to 34% lower than that of pellets produced using forest biomass only. GHG effects due to induced direct and indirect changes in forest carbon stock caused by changes in harvest rotations, changes in land use and in conventional wood production account for 11% to 26% of the overall GHG intensity of pellets produced from forest biomass only; these effects are negative with the use of forest and agricultural biomass. (letter)

BIOENERGIA - Focus on wood in bioenergy research

Energy Technology Data Exchange (ETDEWEB)

Asplund, D. [Jyvaeskylae Science Park, Jyvaeskylae (Finland)

1996-12-31

The most important area of research on wood fuel production is the development of various methods, machines and systems connected to this area, in order to produce economically competitive fuels. The integrated harvesting methods, which supply both raw material to wood products industry and wood fuel for energy production, have been chosen the main research area because they seem to be most promising. The growing amount of small-sized trees ant the need of their first thinnings have created a demand for new harvesting methods. At the moment the economical aspects restrict the harvesting of the first thinning trees either for industrial use or energy production. Research on peat production focuses on the complete use of a bog and on the development of peat production methods and machines. Development work in this area aims at decreasing production costs and also at reducing the drainage water and other elements in environmental load around the peat production sites. The use of bioenergy research will be focused on the small-scale (<20 MW{sub th},) applications. In the long term, the increase of bioenergy in heating of small houses and farms and buildings, as well as in the production of heat and power has been estimated. Research into the conversion of biomass is concentrated on the production of biomass-based liquid fuels

Present and future trends in pellet markets, raw materials, and supply logistics in Sweden and Finland

International Nuclear Information System (INIS)

Selkimaeki, Mari; Mola-Yudego, Blas; Roeser, Dominik; Prinz, Robert; Sikanen, Lauri

2010-01-01

Wood pellets have become an important fuel in heat and power production, and pellet markets are currently undergoing rapid development. In this paper, the pellet markets, raw materials and supply structures are analyzed for Sweden and Finland, based on a database of the current location and production capacity of the pellet producers, complemented with existing reports and literature. In Sweden, a total of 94 pellet plants/producers were identified, producing 1.4 million tonnes of pellets, while the domestic consumption was 1.7 million tonnes, and about 400,000 t of pellets were imported to fulfil the demand in 2007. In Finland, 24 pellet plants/producers were identified and the production was around 330,000 t while the domestic consumption was 117,000 t in 2007. In Finland, pellet market has been long time export oriented, whereas domestic consumption has been growing mainly in the small scale consumer sector, estimated 15,000 households had pellet heating systems in 2008. In the future, the increasing number of pellet users will require a reliable delivery network and good equipment for bulk pellet deliveries. Provision of new raw materials and ensuring the good quality of pellets through the whole production, delivery and handling chain will be fundamental in order to increase the use of pellets and sustain the ability to compete with other fuels. (author)

An analysis of the Green pellet market in Norway; Markedsrapport. Pelletsmarkedet i Midt-Norge

Energy Technology Data Exchange (ETDEWEB)

Ingeberg, Kjetil; Lisleboe, Ole; Langseth, Benedicte; Troemborg, Erik

2010-09-15

This report presents a forecast for a viable green pellets market i mid-Norway in 2020. Its main conclusions are that green pellets are marginally competitive in the building heating market, competitive in some industrial process but not competitive in district heating. If Enova are to achieve a higher market penetration for green pellets, it should strengthen both its ' information and competence building programmes as well as increase financial support to green pellets. In the building heating market, green pellets could expect take a market share up to 15%, or approximately 80 GWh. Under favorable relative energy prices, market share could get significantly higher, i.e. several 100 GWh. In industry, conversion of current light fuel oil consumption could represent approximately 100 GWh Increased use of green pellets would above all reduce investments in heat pumps, both air-to-air (small buildings) and air-to-water (larger buildings), as well as investment in wood chip burning boilers. Consequently, Enova should carefully consider its portfolio of support across technologies as to avoid adverse effects of a unilateral improvement of support to green pellets. (Author)

Controversy. The wood war; Polemique - la guerre du bois

Energy Technology Data Exchange (ETDEWEB)

James, O.

2010-12-15

The author comments the conflict emerging in France between industries exploiting wood for construction and those exploiting it as a heating material for power generation. The first ones accuse the others to steal their raw material, to pull the prices up, and to destabilize the sector. This conflict takes place notably around sawmill wastes which are used either by wood panel fabricators or by wood pellets producers. Both sectors are claiming they are creating more jobs than the other. The French forest indeed offers good opportunities for both sectors, but other countries which are lacking forest surfaces, are buying wood in France. Several issues are matter of discussion: burning wood seems to go against the reduction of greenhouse gas emissions, subsidies awarded to big heater projects. The situation of the wood sector in Austria, Finland and Poland is briefly presented

Cleaner heat from wood. TULISIJA research programme for wood firing technology 1997-1999

International Nuclear Information System (INIS)

1998-01-01

There are 1.3 million wood-burning fireplaces in Finnish homes. The interest in using fireplaces for heating of dwellings has recently been growing strongly. Some 5.6 million cubic meters of firewood is burned in domestic stoves and fireplaces annually. This corresponds to a total of 7.5 terawatthours of energy and amounts to 13 % of all energy used for heating in Finland. The aim of the TULISIJA research programme for wood firing technology (1997-1999) is to assist manufacturers in their efforts to develop the most emission-free, yet efficient, wood firing equipment in the world. Detailed objectives of the TULISIJA programme are: (1) To produce modelling capabilities for the evaluation of different fireplace designs. Capabilities are produced for utilising computer simulation for investigation of the emissions of small-size fireplaces. (2) To establish a measuring place for fireplaces, where manufacturers' equipment designs can be reliably tested according to different standards is to be built, through which the Finnish manufacturers may obtain approvals for their products for different market areas. (3) To enhance co-operation between manufacturers and research institutions. Within the programme, the expertise of researchers in universities and other research institutes is made available to manufacturers - and vice versa. Equally important is the utilisation of international co-operation and making new connections

Pellet production from agricultural raw materials - A systems study

Energy Technology Data Exchange (ETDEWEB)

Nilsson, Daniel; Bernesson, Sven; Hansson, Per-Anders [Department of Energy and Technology, Swedish University of Agricultural Sciences, P.O. Box 7032, SE-75007 Uppsala (Sweden)

2011-01-15

The demand for biofuel pellets has increased considerably in recent years, causing shortage of the traditional raw materials sawdust and wood shavings. In this study, the costs and energy requirements for the production of pellets from agricultural raw materials were analysed. The materials studied were Salix, reed canary grass, hemp, straw, screenings, rape-seed meal, rape cake and distiller's waste. Four production scales were analysed, having an annual output of 80,000, 8000, 800 and 80 tonnes of pellets per year. It was concluded that the raw materials of greatest interest were Salix and reed canary grass. They had competitive raw material costs and acceptable fuel properties and could be mixed with sawdust in existing large-scale pelleting factories. Straw had low production costs but can cause serious ash-related problems and should, as also is the case for screenings, be avoided in small-scale burners. Hemp had high raw material costs and is of less commercial interest, while distiller's waste, rape-seed meal and rape cake had higher alternative values when used as protein feed. The scale of production had a crucial influence on production costs. The machinery was used much more efficiently in large-scale plants, resulting in clear cost savings. Small-scale pelleting, both static and mobile, required cheap raw materials, low labour costs and long utilisation times to be profitable. In most cases, briquetting would be more commercially viable. The energy use in manufacturing pellets from air-dried crops was generally no higher than when moist sawdust was used as the raw material. (author)

Proceedings of the 8. biennial residual wood conference

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

This conference highlighted practical strategies for managing and utilizing residual wood as a true industry resource. Examples of successful wood energy projects were presented along with the technology and products of more than 30 companies involved in the residual wood business. The topics of discussion ranged from biomass supplies, quality issues, and harvesting guidelines to emerging biomass technologies, project overviews, and financing. The presentations outlined the many opportunities that exist for the forest industry to produce energy from biostock, such as healthy and diseased trees, underbrush, sawdust, wood chips, wood pulp and black liquor. Increasing fuel and energy costs along with advances in technology are improving the economy of forest-based biorefineries. The presentations showed how the industry can gain revenue from residual wood, which is steadily becoming a more valuable resource for pellet production and energy generation The conference featured 20 presentations, of which 3 have been catalogued separately for inclusion in this database. refs., tabs., figs.

Wood energy and air quality. Synthetic report

International Nuclear Information System (INIS)

2009-07-01

This report presents and comments some reference data about the current and prospective (2010, 2020) pollutant emissions through wood combustion as a source of energy. It indicates and compares greenhouse gas emissions by the different sources for household, collective and industrial heating (fuel, gas, electricity, pellets, logs, grinds, wood wastes), gives an overview of atmospheric emissions due to biomass combustion. It compares emissions due to wood combustion with respect to the activity sectors and to combustion equipment. It highlights the challenges of the development of the household sector in terms of improvement and renewal of the quality of the burning equipment. It comments the implemented policies which notably aim at reducing the emission of particles, and at defining quality labels

Contributions to advances in blend pellet products (BPP) research on molecular structure and molecular nutrition interaction by advanced synchrotron and globar molecular (Micro)spectroscopy.

Science.gov (United States)

Guevara-Oquendo, Víctor H; Zhang, Huihua; Yu, Peiqiang

2018-04-13

To date, advanced synchrotron-based and globar-sourced techniques are almost unknown to food and feed scientists. There has been little application of these advanced techniques to study blend pellet products at a molecular level. This article aims to provide recent research on advanced synchrotron and globar vibrational molecular spectroscopy contributions to advances in blend pellet products research on molecular structure and molecular nutrition interaction. How processing induced molecular structure changes in relation to nutrient availability and utilization of the blend pellet products. The study reviews Utilization of co-product components for blend pellet product in North America; Utilization and benefits of inclusion of pulse screenings; Utilization of additives in blend pellet products; Application of pellet processing in blend pellet products; Conventional evaluation techniques and methods for blend pellet products. The study focus on recent applications of cutting-edge vibrational molecular spectroscopy for molecular structure and molecular structure association with nutrient utilization in blend pellet products. The information described in this article gives better insight on how advanced molecular (micro)spectroscopy contributions to advances in blend pellet products research on molecular structure and molecular nutrition interaction.

Wood, the indigenous energy source. 1100 plants built in 20 years, all of them 'Swiss made'

International Nuclear Information System (INIS)

Wahlen, B.

1999-01-01

The company HOBAG Brienz, Ltd., specialised in the field of automatic wood-burning plants, continuously developed its unique system over the past 20 years and has more than 1100 satisfied clients in Switzerland as well as in foreign countries. It is equally dealing with log boilers, wood chip boilers, or pellet boilers. Nowadays, the company is seen as the market leader for modern, full automatic log-burning plants and wood conditioning equipment including containers for logs or wood chips

NIR techniques create added values for the pellet and biofuel industry.

Science.gov (United States)

Lestander, Torbjörn A; Johnsson, Bo; Grothage, Morgan

2009-02-01

A 2(3)-factorial experiment was carried out in an industrial plant producing biofuel pellets with sawdust as feedstock. The aim was to use on-line near infrared (NIR) spectra from sawdust for real time predictions of moisture content, blends of sawdust and energy consumption of the pellet press. The factors varied were: drying temperature and wood powder dryness in binary blends of sawdust from Norway spruce and Scots pine. The main results were excellent NIR calibration models for on-line prediction of moisture content and binary blends of sawdust from the two species, but also for the novel finding that the consumption of electrical energy per unit pelletized biomass can be predicted by NIR reflectance spectra from sawdust entering the pellet press. This power consumption model, explaining 91.0% of the variation, indicated that NIR data contained information of the compression and friction properties of the biomass feedstock. The moisture content model was validated using a running NIR calibration model in the pellet plant. It is shown that the adjusted prediction error was 0.41% moisture content for grinded sawdust dried to ca. 6-12% moisture content. Further, although used drying temperatures influenced NIR spectra the models for drying temperature resulted in low prediction accuracy. The results show that on-line NIR can be used as an important tool in the monitoring and control of the pelletizing process and that the use of NIR technique in fuel pellet production has possibilities to better meet customer specifications, and therefore create added production values.

Pelletization of fine coals. Final report

Energy Technology Data Exchange (ETDEWEB)

Sastry, K.V.S.

1995-12-31

Coal is one of the most abundant energy resources in the US with nearly 800 million tons of it being mined annually. Process and environmental demands for low-ash, low-sulfur coals and economic constraints for high productivity are leading the coal industry to use such modern mining methods as longwall mining and such newer coal processing techniques as froth flotation, oil agglomeration, chemical cleaning and synthetic fuel production. All these processes are faced with one common problem area--fine coals. Dealing effectively with these fine coals during handling, storage, transportation, and/or processing continues to be a challenge facing the industry. Agglomeration by the unit operation of pelletization consists of tumbling moist fines in drums or discs. Past experimental work and limited commercial practice have shown that pelletization can alleviate the problems associated with fine coals. However, it was recognized that there exists a serious need for delineating the fundamental principles of fine coal pelletization. Accordingly, a research program has been carried involving four specific topics: (i) experimental investigation of coal pelletization kinetics, (ii) understanding the surface principles of coal pelletization, (iii) modeling of coal pelletization processes, and (iv) simulation of fine coal pelletization circuits. This report summarizes the major findings and provides relevant details of the research effort.

U.S. Pellet Industry Analysis

Energy Technology Data Exchange (ETDEWEB)

Corrie I. Nichol; Jacob J. Jacobsen; Richard D. Boardman

2011-06-01

This report is a survey of the U.S. Pellet Industry, its current capacity, economic drivers, and projected demand for biomass pellets to meet future energy consumption needs. Energy consumption in the US is projected to require an ever increasing portion of renewable energy sources including biofuels, among which are wood, and agrictulrual biomass. Goals set by federal agencies will drive an ever increasing demand for biomass. The EIA projections estimate that renewable energy produced by 2035 will be roughly 10% of all US energy consumption. Further analysis of the biofuels consumption in the US shows that of the renewable energy sources excluding biofuels, nearly 30% are wood or biomass waste. This equates to roughly 2% of the total energy consumption in the US coming from biomass in 2009, and the projections for 2035 show a strong increase in this amount. As of 2009, biomass energy production equates to roughly 2-2.5 quadrillion Btu. The EIA projections also show coal as providing 21% of energy consumed. If biomass is blended at 20% to co-fire coal plants, this will result in an additional 4 quadrillion Btu of biomass consumption. The EISA goals aim to produce 16 billion gal/year of cellulosic biofuels, and the US military has set goals for biofuels production. The Air Force has proposed to replace 50% of its domestic fuel requirements with alternative fuels from renewable sources by 2016. The Navy has likewise set a goal to provide 50% of its energy requirements from alternative sources. The Department of Energy has set similarly ambitious goals. The DOE goal is to replace 40% of 2004 gasoline use with biofuels. This equates to roughly 60 billion gal/year, of which, 45 billion gal/year would be produced from lignocellulosic resources. This would require 530 million dry tons of herbaceous and woody lignocellulosic biomass per year.

Experimental characterization, modeling and simulation of a wood pellet micro-combined heat and power unit used as a heat source for a residential building

Energy Technology Data Exchange (ETDEWEB)

Thiers, Stephane; Aoun, Bernard; Peuportier, Bruno [MINES ParisTech, CEP - Centre Energetique et Procedes, 60 Boulevard St Michel, 75272 Paris Cedex 06 (France)

2010-06-15

Cogeneration provides heat and power in a more efficient way than separate production. Micro-cogeneration (micro-CHP) is an emerging solution for the improvement of energy and environmental assessments of residential buildings. A wood pellet Stirling engine micro-CHP unit has been studied in order to characterize its annual performance when integrated to a building. First, through a test bench experiment, both transient and steady state behaviors of the micro-CHP unit have been characterized and modeled. Then a more complete model representing a hot water and heating system including the micro-CHP unit and a stratified storage tank has been carried out. This model has been coupled to a building model. A sensitivity analysis by simulation shows that the dimensioning of different elements of the system strongly influences its global energy performance. (author)

Export versus domestic market opportunities

International Nuclear Information System (INIS)

Melin, S.

2006-01-01

This presentation analyzed the current global wood pellet market and evaluated some of the forces currently driving market expansion. Global wood pellet production statistics were also presented. Large forest companies are now expanding into the energy sector and seeking to produce processing heat from biomass in addition to creating value-added products such as wood pellets, ethanol and electricity. The European biomass action plan has promised to increase production of energy from biomass from 4 per cent to 8 per cent by 2010. Various biomass boiler eco-directives have been established internationally, and some countries in Europe are now aggressively promoting the use of combined heat and power (CHP) systems. Biofuels mixing quotas have been established in various countries as well as tax relief plans for users of bio-fuels. As a result of these developments, along with various new directives, wood pellet consumption in Europe has increased from approximately 1 million tonnes in 2000 to 5 million tonnes in 2005. Consumption of wood pellets in Canada has increased only marginally in the same time period. While Canada currently exported 330,000 tonnes of wood pellets to Europe in 2006, it is expected that exports will increase to 800,000 tonnes by 2010. Other potential markets for Canadian wood pellets include South America, South Africa, Japan, and China. Production of wood pellets in China is expected to increase from current negligible production figures to approximately 50 million tonnes by 2020. Biomass research and development activities in Europe and North America are continuing to improve the calorific value of wood pellets and improve their mechanical strength. Researchers are also investigating methods of lowering wood pellet production costs. refs., tabs., figs

IAEA technical committee meeting on pellet injection

International Nuclear Information System (INIS)

1993-01-01

The IAEA Technical Committee Meeting on Pellet Injection, May 10-12, 1993, at the Japan Atomic Energy Research Institute, Naka, Ibaraki-ken, Japan, was held to review the latest results on pellet injection and its effects on plasma confinement. In particular, topics included in the meeting include (i) pellet ablation and particle fueling results, (ii) pellet injection effects on confinement, including improved confinement modes, edge effects, magnetohydrodynamic activity and impurity transport, and (iii) injector technology and diagnostics using pellets. About 30 experts attended and 23 papers were presented. Refs, figs and tabs

Performance of a pellet boiler fired with agricultural fuels

International Nuclear Information System (INIS)

Carvalho, Lara; Wopienka, Elisabeth; Pointner, Christian; Lundgren, Joakim; Verma, Vijay Kumar; Haslinger, Walter; Schmidl, Christoph

2013-01-01

Highlights: ► Performance evaluation of a pellet boiler operated with different agricultural fuels. ► Agricultural fuels could be burn in the tested boiler for a certain period of time. ► All the fuels (except straw and Sorghum) satisfied the European legal requirements. ► Boilers for burning agricultural fuels should have a flexible control system. - Abstract: The increasing demand for woody biomass increases the price of this limited resource, motivating the growing interest in using woody materials of lower quality as well as non-woody biomass fuels for heat production in Europe. The challenges in using non-woody biomass as fuels are related to the variability of the chemical composition and in certain fuel properties that may induce problems during combustion. The objective of this work has been to evaluate the technical and environmental performance of a 15 kW pellet boiler when operated with different pelletized biomass fuels, namely straw (Triticum aestivum), Miscanthus (Miscanthus × giganteus), maize (Zea mays), wheat bran, vineyard pruning (from Vitis vinifera), hay, Sorghum (Sorghum bicolor) and wood (from Picea abies) with 5% rye flour. The gaseous and dust emissions as well as the boiler efficiency were investigated and compared with the legal requirements defined in the FprEN 303-5 (final draft of the European standard 303-5). It was found that the boiler control should be improved to better adapt the combustion conditions to the different properties of the agricultural fuels. Additionally, there is a need for a frequent cleaning of the heat exchangers in boilers operated with agricultural fuels to avoid efficiency drops after short term operation. All the agricultural fuels satisfied the legal requirements defined in the FprEN 303-5, with the exception of dust emissions during combustion of straw and Sorghum. Miscanthus and vineyard pruning were the best fuels tested showing comparable emission values to wood combustion

Present status of laser fusion fuel pellet

International Nuclear Information System (INIS)

Nakai, Sadao; Mima, Kunioki; Norimatsu, Takayoshi; Takagi, Masaru.

1986-01-01

Accompanying the advance of pellet implosion experiment, the data base required for fuel pellet design has been steadily accumulated. The clarification of the physics related to the process of absorbing laser beam, energy transport, the generation of ablative pressure, the hydrodynamic mechanism of implosion, the energy transmission to fuel core and so on progressed, and the design data supported by these results are prepared. Based on the data base like this, the design of fuel pellets taking the optimization of implosion in consideration is carried out. The various fuel pellets designed in this way are tested for their effectiveness by implosion experiment. For this purpose, the high performance measurement of implosion and the high accuracy manufacture of fuel pellets become very important. In this paper, the present state of the research on the method of laser implosion, the example of pellet design and the law of proportion, the manufacturing techniques of the fuel pellets having various structures, the techniques dealing with tritium and so on is summarized, and the direction of future research and development is ascertained. At present, implosion experiment is carried out mostly by hanging a pellet target with a fiber of several μm diameter, but the fiber impairs the symmetry of implosion. The levitation techniques without contact is required. (Kako, I.)

Table-top pellet injector (TATOP) for impurity pellet injection

Energy Technology Data Exchange (ETDEWEB)

Szepesi, Tamás, E-mail: szepesi.tamas@wigner.mta.hu [Wigner RCP, RMI, Konkoly Thege 29-33, H-1121 Budapest (Hungary); Herrmann, Albrecht [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Kocsis, Gábor; Kovács, Ádám; Németh, József [Wigner RCP, RMI, Konkoly Thege 29-33, H-1121 Budapest (Hungary); Ploeckl, Bernhard [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

2015-10-15

Highlights: • A portable pellet injector for solid state pellets was designed. • Aims to study ELM triggering potential of impurity pellets. • Aims for multi-machine comparison of pellet–plasma interaction. • Max. pellet speed: 450 m/s, max. rate: 25 Hz. • Pellet size: 0.5–1.5 mm (diameter). - Abstract: A table-top pellet injector (TATOP) has been designed to fulfill the following scientific aims: to study the ELM triggering potential of impurity pellets, and to make pellet injection experiments comparable over several fusion machines. The TATOP is based on a centrifugal accelerator therefore the complete system is run in vacuum, ensuring the compatibility with fusion devices. The injector is able to launch any solid material (stable at room temperature) in form of balls with a diameter in the 0.5–1.5 mm range. The device hosts three individual pellet tanks that can contain e.g. pellets of different materials, and the user can select from those without opening the vacuum chamber. A key element of the accelerator is a two-stage stop cylinder that reduces the spatial scatter of pellets exiting the acceleration arm below 6°, enabling the efficient collection of all fired pellets. The injector has a maximum launch speed of 450 m/s. The launching of pellets can be done individually by providing TTL triggers for the injector, giving a high level of freedom for the experimenter when designing pellet trains. However, the (temporary) firing rate cannot be larger than 25 Hz. TATOP characterization was done in a test bed; however, the project is still in progress and before application at a fusion oriented experiment.

Determination Of Simulated Pellet To Pellet Gap Using Neutron Radiography

International Nuclear Information System (INIS)

Kusnowo, A.

1996-01-01

The defect on the irradiated fuel element could be detected using neutron radiography. The defect could occurred in pellet to pellet gap, cladding, or even cladding to pellet gap. An investigations has been performed to detect pellet to pellet gap defect that might occur in an irradiated fuel element. An Al foil of 0,1; 0,2; 0,3; und 0,4 mm was inserted between pellets to simulate various pellet to pellet gap. The neutron radiography used had power of 700 kW. The result showed that this simulation represented well enough problems that irradiated fuel element may experience

Intelligent Automated Nuclear Fuel Pellet Inspection System

International Nuclear Information System (INIS)

Keyvan, S.

1999-01-01

At the present time, nuclear pellet inspection is performed manually using naked eyes for judgment and decisionmaking on accepting or rejecting pellets. This current practice of pellet inspection is tedious and subject to inconsistencies and error. Furthermore, unnecessary re-fabrication of pellets is costly and the presence of low quality pellets in a fuel assembly is unacceptable. To improve the quality control in nuclear fuel fabrication plants, an automated pellet inspection system based on advanced techniques is needed. Such a system addresses the following concerns of the current manual inspection method: (1) the reliability of inspection due to typical human errors, (2) radiation exposure to the workers, and (3) speed of inspection and its economical impact. The goal of this research is to develop an automated nuclear fuel pellet inspection system which is based on pellet video (photographic) images and uses artificial intelligence techniques

Technical-economic study of the implementation of small pellet units in the Provence-Alpes-Cote d'Azur region. Phases 1 and 2: Frame-working of the regional sector, explanation of possible fabrication processes

International Nuclear Information System (INIS)

2007-09-01

A first part of this report proposes an analysis of the existing supply, demand and competition for the wood pellet production sector. More precisely, it proposes a brief analysis of the European pellet market and of its operation, a study of the individual PACA market (pellet market, actors, market price and evolutions in the region), and a competitive analysis. The second part reports the study of mobilisable resources. It proposes a resource analysis (potential resource identification, analysis of the regional wood sector production, other resource usages, mobilisable resources), a market and resource synthesis, an overview of possible processes (with or without drying), and a discussion of criteria to be taken into account. The third part reports a technical-economic study for the implementation of small wood pellet production units in the region. It addresses the different possible processes, compares them in terms of social and environmental assessments, and in terms of global feasibility. It also proposes a decision-making tool which comprises criteria to be taken into account and elements of thought related to regional policy

Life cycle adaption of biofuel ashes. Evaluation of new techniques for pelletizing of biofuel ashes, especially regarding operational properties and environmental effects in the forest after ash recycling. Stage 1

International Nuclear Information System (INIS)

Loevgren, Linnea; Lundmark, Jan-Erik; Jansson, Charlotta

2000-11-01

The aim of the project 'Adaptation of Wood Ashes to Recycling' is to evaluate a new technique - roll pelleting - for making wood ash suitable for reuse as a fertiliser for woodland. The project is being carried out at the forest product companies AssiDomaen and Stora Enso. The main financier is the Swedish National Energy Administration. Other financiers are AssiDomaen, Stora Enso, The Thermal Engineering Research Institute and The Forestry Research Institute of Sweden. The project has involved the construction of a full-scale roll pelleter in a mobile container and its trial operation at two Swedish pulp and paper mills. The leaching properties of the ash products were studied with a laboratory method. In addition, the effects of ash fertilisation with these products are being studied in a four-year field trial. Effects on soil pH, nutrient supply, soil water chemistry and ground vegetation are being evaluated by The Forestry Research Institute of Sweden and will be reported separately in the year 2003. In a laboratory prestudy, the leaching properties of pellets from twelve different ash products made in a laboratory prototype machine were evaluated. The ash products were made from residues from the AssiDomaen Froevi mill and the Stora Enso Fors mill. Fly ash from Froevi was used alone and mixed with green liquor sludge and lime sludge respectively. Fly ash from Fors was also used alone and mixed with coating colour. The laboratory method used for the evaluation of leaching properties is the method developed by IVL The Swedish Environmental Research Institute Ltd. The results show that the progress of the leaching of roll pelleted ash is significantly slower than for the corresponding crushed product and a reference lime product. The speed of leaching, measured as acid neutralisation capacity, ANC, was significantly lower for the roll pelleted ash compared to self-hardened and crushed ash products. Because of the high content of calcium, lime has on the whole, a

Semivolatile and Volatile Organic Compound Emissions from Wood-Fired Hydronic Heaters

Science.gov (United States)

Four commercially available HH technologies were studied: a single-stage combustor with natural updraft, a three-stage downdraft combustion system, a bottom-fed pellet burner, and a two-stage heater with both a combustion and gasification chamber. The fuel consisted of three wood...

Pellet dimension checker

International Nuclear Information System (INIS)

Marmo, A.R.

1980-01-01

A pellet dimension checker was developed for use in making nuclear-fuel pellets. This checker eliminates operator handling of the pellet but permits remote-monitoring of the operation, and is thus suitable for mass production of green fuel pellets particularly in reprocessing plants handling irradiated uranium or plutonium. It comprises a rotatable arm for transferring a pellet from a conveyor to several dimensional measuring stations and back to the conveyor if the dimensions of the pellet are within predetermined limits. If the pellet is not within the limits, the arm removes the pellet from the process stream. (DN)

Circular economy in drinking water treatment: reuse of ground pellets as seeding material in the pellet softening process.

Science.gov (United States)

Schetters, M J A; van der Hoek, J P; Kramer, O J I; Kors, L J; Palmen, L J; Hofs, B; Koppers, H

2015-01-01

Calcium carbonate pellets are produced as a by-product in the pellet softening process. In the Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high-potential market segments such as paper and glass. Substitution of the sand grain with a calcite grain (100% calcium carbonate) is in principle possible, and could significantly improve the pellet quality. In this study, the grinding and sieving of pellets, and the subsequent reuse as seeding material in pellet softening were tested with two pilot reactors in parallel. In one reactor, garnet sand was used as seeding material, in the other ground calcite. Garnet sand and ground calcite performed equally well. An economic comparison and a life-cycle assessment were made as well. The results show that the reuse of ground calcite as seeding material in pellet softening is technologically possible, reduces the operational costs by €38,000 (1%) and reduces the environmental impact by 5%. Therefore, at the drinking water facility, Weesperkarspel of Waternet, the transition from garnet sand to ground calcite will be made at full scale, based on this pilot plant research.

Diffusion of innovative domestic heating systems and multi-storey wood-framed buildings in Sweden

Energy Technology Data Exchange (ETDEWEB)

Mahapatra, Krushna

2007-10-15

The diffusion of innovations that promote sustainable use of forest resources and energy efficiency is important for reducing greenhouse gas emission and dependency on oil. In this thesis the 'systems of innovation' (SI) approach is used to analyse the diffusion of multi-storey wood-framed buildings and wood pellet heating systems in Sweden. The diffusion of an innovative heating system (IHS) is influenced by the diffusion of other types of IHSs, making it complex to analyse the diffusion of all these systems simultaneously using the SI approach. Hence, an 'adopter-centric' approach was used, as homeowners make the decision to adopt an IHS, which affects the rate of adoption of that system. The SI analyses showed that several sources of path dependency, resulting from the establishment and growth of the concrete-based construction system over the past 100 years, hinder the expansion of a wood-based multi-storey construction system. However, development of the wood construction system was possible due to government policies and funding, the wood industry's interest in expanding the market for value-added wood products, and the involvement of the wood research community. The growth of the pellet market was supported by national energy policy, the abundance of raw material and broad dissemination of district heating systems. However, a lack of co-ordination between the pellet and equipment suppliers in the early phase of market development, high annual operating cost, lack of information, dissatisfaction among early adopters and technology lock-in contributed to its relatively slow growth. The adopter-centric approach included household questionnaire surveys: one covering the whole of Sweden in 2004 involving 1500 randomly selected homeowners with any type of heating system, and another in the city of Oestersund in 2005 of 700 homeowners who had resistance heaters. The same homeowners in Oestersund were re-surveyed in 2006 to analyse the

Exploring policy options for a transition to sustainable heating system diffusion using an agent-based simulation

International Nuclear Information System (INIS)

Maya Sopha, Bertha; Kloeckner, Christian A.; Hertwich, Edgar G.

2011-01-01

Change in home heating to more efficient and renewable systems is important for a sound climate policy. The present paper aims to identify potential interventions for the uptake of wood-pellet heating in Norway using an agent-based model (ABM). The theoretically based, empirically founded, agent-based simulation demonstrates that financial support, i.e., a stable wood-pellet price, and technical development, i.e., functional reliability improvement, have to be established all at the same time for a successful wood-pellet market to start. Furthermore, a soft intervention through persuading households to use environmentally beneficial heating system is not a promising driver for wood-pellet diffusion. Limitations and suggestions for future work are also discussed. - Research highlights: → The theoretically based, empirically founded, agent-based simulation is applied to investigate potential policy options toward diffusion of wood-pellet heating in Norway. → Relative advantages are necessary for wood-pellet heating to be adopted, consistent with Diffusion of Innovation theory (). → Simultaneous development is also required for further uptake of wood-pellet heating, supporting the existing empirical hypothesis by . → Persuading households to use environmentally friendly heating system is not a promising driver, in line with empirical finding of , who investigated psychological factors underlying the adoption of wood-pellet heating.

Exploring policy options for a transition to sustainable heating system diffusion using an agent-based simulation

Energy Technology Data Exchange (ETDEWEB)

Maya Sopha, Bertha, E-mail: bertha.sopha@ntnu.n [Industrial Ecology Programme and Department of Energy and Process Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Kloeckner, Christian A. [Department of Psychology, Section for Risk Psychology, Environment and Safety (RIPENSA), Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Hertwich, Edgar G. [Industrial Ecology Programme and Department of Energy and Process Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)

2011-05-15

Change in home heating to more efficient and renewable systems is important for a sound climate policy. The present paper aims to identify potential interventions for the uptake of wood-pellet heating in Norway using an agent-based model (ABM). The theoretically based, empirically founded, agent-based simulation demonstrates that financial support, i.e., a stable wood-pellet price, and technical development, i.e., functional reliability improvement, have to be established all at the same time for a successful wood-pellet market to start. Furthermore, a soft intervention through persuading households to use environmentally beneficial heating system is not a promising driver for wood-pellet diffusion. Limitations and suggestions for future work are also discussed. - Research highlights: {yields} The theoretically based, empirically founded, agent-based simulation is applied to investigate potential policy options toward diffusion of wood-pellet heating in Norway. {yields} Relative advantages are necessary for wood-pellet heating to be adopted, consistent with Diffusion of Innovation theory (). {yields} Simultaneous development is also required for further uptake of wood-pellet heating, supporting the existing empirical hypothesis by . {yields} Persuading households to use environmentally friendly heating system is not a promising driver, in line with empirical finding of , who investigated psychological factors underlying the adoption of wood-pellet heating.

AFBnet - Wood and field energy information from Europe

International Nuclear Information System (INIS)

Alakangas, E.

2001-01-01

The objective of EU's ALTENER program is to promote the use of renewable energy sources. The European bioenergy network AFBnet produces and delivers information on bioenergy research and utilization of them in different countries. Import and export of biofuels, as well as the prices of biofuels in twenty European countries have been studied during past two years. The potential of combined heat and power generation with biofuels has also been estimated. The network has evaluated these projects and the factors, which have affected the successfulness and unsuccessfulness of the projects in different countries. In Finland the promotion of the utilization of wood fuels in municipal projects was evaluated in a 'Heat Entrepreneur competition' carried out first time in 2000. AFBnet analyzed the operation of 21 plants using mixed fuels as energy sources. One of the objectives was to collect information on experiences of production and processing phase of fuels at district heating and power plants in Finland, Italy, Austria, Portugal, Sweden, Germany and Denmark. The plants consumed different kinds of biofuels (industrial wood residues, straw and other agricultural wastes) and the mixture of them. Plants using different combustion technologies (grate, fluidized bed and pulverized fuel combustion, and biomass gasifiers). The consumption rate of wood and agricultural biofuels in plants was about 30% of the total fuel consumption. The main mixed fuel was coal, the share of which was 28% of the total. A detailed report has been published on all the plants. The reports analyze the fuel production and processing chains of the plants up to the boiler. Data was gathered also from the investments and maintenance costs of the plants. In EU countries there is no comprehensive survey on the prices of biofuels. Only Sweden publishes the prices of biofuels regularly. AFBnet collected in 1999 data on fuel prices, import and export of the fuels, and present utilization and potential of

U.S. Department Of Energy's nuclear engineering education research: highlights of recent and current research-II. 5. Automation of Nuclear Fuel Pellet Quality Control

International Nuclear Information System (INIS)

Keyvan, Shahla; Song, Xiaolong

2001-01-01

At the present time, nuclear fuel pellet inspection is performed by humans using the naked eye for judgment and decision making as to whether to accept or reject the pellet. Unnecessary re-fabrication of pellets will be costly, and having too many low-quality pellets in a fuel assembly is unacceptable. The current practice of pellet inspection by humans is tedious and subject to inconsistencies and error. In addition, manual inspection is cumbersome since the inspector must keep the pellet at arm's length and must wear glasses to protect the lenses of his or her eyes. The pellets are taken from a pellet sizing machine, dumped onto a rack, and shaken into rows; they are then viewed as a group. The entire group is rotated 90 deg four times to provide the inspector with a 360-deg view of each pellet. The pellets are examined for certain types of cracks, chips, and unusual markings, i.e., water stains and machine banding. These defects appear at any location on the pellet surface image with different intensity, size, shape, and background noise. Figure 1 shows typical defective fuel pellets with chip, banded, and end defects. The goal of this work is to automate the pellet inspection process. A prototype of such an inspection system is developed. The system examines photographic images of pellets using various artificial intelligence techniques for image analysis and defect classification. Figure 2 shows the user interface of this inspection system, which is built using Java programming language. A total of 252 pellets with various defects was available for this research. Each pellet was photographed four times at rotations of 90 deg. The resultant black-and-white negatives were scanned into the computer in 256 gray scale mode. The inspection of a fuel pellet by image analysis involves several steps, as described in Fig. 3 and as follows: Step 1-On-line image conversion: This process involves on-line digitization of the input image. Step 2-Reference model: The second

Repeating pneumatic pellet injector in JAERI

Energy Technology Data Exchange (ETDEWEB)

Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment); Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

1992-09-01

A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author).

Repeating pneumatic pellet injector in JAERI

International Nuclear Information System (INIS)

Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi; Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

1992-09-01

A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author)

Technical development of a retrofit wood burner for coal under-fed stokers in County Durham, and set up of demonstration facility

Energy Technology Data Exchange (ETDEWEB)

Smith, N.

2002-07-01

Durham County Council wishes to convert its coal-burning solid fuel boilers to make use of readily-available waste wood dust. It is intended that the wood dust be converted to pelleted fuel. The emphasis was on cost-cutting rather than boiler efficiency. The experimental studies were carried out at two schools where the boilers were welded steel and cast iron sectional boilers. Factors studied were air supply to the boilers, fuel feed systems, fuel storage, fuel delivery and pelletization. The results have shown that operating costs of wood burning boilers are a little greater than coal-burning but this is slightly offset by savings elsewhere. The environmental benefits were significant in terms of lower emissions from the boilers, reduced road transport, and the wood waste is no longer sent to landfill. Further areas of study are recommended. The contractor for this study was North Energy Associates Ltd, and the study was part of the DTI Sustainable Energy Programme.

The pellet handbook: the production and thermal utilisation of pellets

National Research Council Canada - National Science Library

Obernberger, Ingwald; Thek, Gerold

2010-01-01

...: - International overview of standards for pellets - Evaluation of raw materials and raw material potentials - Quality and properties of pellets - Technical evaluation of the pellet production process...

A Characterization Research of UO2 Powder for UO2 Pellet Fabrication of Candu Type

International Nuclear Information System (INIS)

Rachmawati, M.

1998-01-01

A characterization research of of UO 2 powder for UO 2 pellet fabrication of Candu type is reported in this paper. The research has been conducted by characterizing sinterability, compactibility, and compressibility of UO 2 (Cameco) without a pre-compacting and UO 2 powder the result of a pre-compacting. The pre-compacting UO 2 powder has been done to have particle size to less than 150 mu (150-800) mu, and more than 800 mu with distribution varied. Sinterability of each group of particle sizes is analyzed using Thermogravimetric-Differential Thermal Analysis (TG-DTA). Then the final compacting to the powder is done using compaction pressure varied from 1 MP to 4 MP to the all groups of the particle sizes to find the optimum pressure by measuring the density and mechanical strength of the UO 2 green pellet. Both measurements are performed using Micrometer and Universal Testing Machine respectively. The result of this investigation shows that the group of UO 2 powder with no pre-compacting with particle size of less than 150 mu with 60% distribution and (150-800) mu size with 40% distribution are the UO 2 pellets which are eligible in terms of their density and mechanical strength

Pellet-press-to-sintering-boat nuclear fuel pellet loading system

International Nuclear Information System (INIS)

Bucher, G.D.

1988-01-01

This patent describes a system for loading nuclear fuel pellets into a sintering boat from a pellet press which ejects newly made the pellets from a pellet press die table surface. The system consists of: (a) a bowl having an inner surface, a longitudinal axis, an open and generally circular top of larger diameter, and an open and generally circular bottom of smaller diameter; (b) means for supporting the bowl in a generally upright position such that the bowl is rotatable about its longitudinal axis; (c) means for receiving the ejected pellets proximate the die table surface of the pellet press and for discharging the received pellets into the bowl at a location proximate the inner surface towards the top of the bowl with a pellet velocity having a horizontal component which is generally tangent to the inner surface of the bowl proximate the location; (d) means for rotating the bowl about the longitudinal axis such that the bowl proximate the location has a velocity generally equal, in magnitude and direction, to the horizontal component of the pellet velocity at the location; and (e) means for moving the sintering boat generally horizontally beneath and proximate the bottom of the bowl

Climate, economic, and environmental impacts of producing wood for bioenergy

Science.gov (United States)

Birdsey, Richard; Duffy, Philip; Smyth, Carolyn; Kurz, Werner A.; Dugan, Alexa J.; Houghton, Richard

2018-05-01

Increasing combustion of woody biomass for electricity has raised concerns and produced conflicting statements about impacts on atmospheric greenhouse gas (GHG) concentrations, climate, and other forest values such as timber supply and biodiversity. The purposes of this concise review of current literature are to (1) examine impacts on net GHG emissions and climate from increasing bioenergy production from forests and exporting wood pellets to Europe from North America, (2) develop a set of science-based recommendations about the circumstances that would result in GHG reductions or increases in the atmosphere, and (3) identify economic and environmental impacts of increasing bioenergy use of forests. We find that increasing bioenergy production and pellet exports often increase net emissions of GHGs for decades or longer, depending on source of feedstock and its alternate fate, time horizon of analysis, energy emissions associated with the supply chain and fuel substitution, and impacts on carbon cycling of forest ecosystems. Alternative uses of roundwood often offer larger reductions in GHGs, in particular long-lived wood products that store carbon for longer periods of time and can achieve greater substitution benefits than bioenergy. Other effects of using wood for bioenergy may be considerable including induced land-use change, changes in supplies of wood and other materials for construction, albedo and non-radiative effects of land-cover change on climate, and long-term impacts on soil productivity. Changes in biodiversity and other ecosystem attributes may be strongly affected by increasing biofuel production, depending on source of material and the projected scale of biofuel production increases.

From a single pellet press to a bench scale pellet mill - Pelletizing six different biomass feedstocks

DEFF Research Database (Denmark)

Puig Arnavat, Maria; Shang, Lei; Sárossy, Zsuzsa

2016-01-01

The increasing demand for biomass pellets requires the investigation of alternative raw materials for pelletizetion. In the present paper, the pelletization process of fescue, alfalfa, sorghum, triticale, miscanthus and willow is studied to determine if results obtained in a single pellet press (...

PELLET: a computer routine for modeling pellet fueling in tokamak plasmas

International Nuclear Information System (INIS)

Houlberg, W.A.; Iskra, M.A.; Howe, H.C.; Attenberger, S.E.

1979-01-01

Recent experimental results of frozen hydrogenic pellet injection into hot tokamak plasmas and substantial agreement with theoretical predictions have led to a much greater interest in pellets as a means of refueling plasmas. The computer routine PELLET has been developed and used as an aid in assessing pellet ablation models and the effects of pellets on plasma behavior. PELLET provides particle source profiles under various options for the ablation model and can be coupled either to a fluid transport code or to a brief routine which supplies the required input parameters

Effect of policies on pellet production and forests in the U.S. South: a technical document supporting the Forest Service update of the 2010 RPA Assessment

Science.gov (United States)

Karen L. Abt; Robert C. Abt; Christopher S. Galik; Kenneth E. Skog

2014-01-01

Current policies in the European Union (EU) requiring renewable and low greenhouse gas-emitting energy are affecting wood products manufacturing and forests in the United States. These policies have led to increased U.S. pellet production and export to the EU, which has in turn affected U.S. forests and other wood products manufacturing. At this time, the primary...

Bioenergy Research Programme, Yearbook 1995. Production of wood fuels; Bioenergian tutkimusohjelma, vuosikirja 1995. Puupolttoaineen tuotantotekniikka

Energy Technology Data Exchange (ETDEWEB)

Alakangas, E [ed.

1997-12-31

Bioenergy Research Programme is one of the energy technology research programmes of the Technology Development Center TEKES. The aim of the Bioenergy Research Programme is to increase, by using technical research and development, the economically profitable and environmentally sound utilisation of bioenergy, to improve the competitiveness of present peat and wood fuels, and to develop new competitive fuels and equipment related to bioenergy. The funding for 1995 was nearly 52 million FIM and the number of projects 66. The main goal of the wood fuels research area is to develop new production methods in order to decrease the production costs to the level of imported fuels. The total potential of the wood fuel use should be at least 1.0 million toe/a (5.5 million m{sup 3}). During the year 1995 There were over 30 projects concerning the production of wood derived fuels going on. Nearly half of them focused on integrated production of pulp wood and wood fuel. About ten projects was carried out to promote the wood fuel production from logging residues. Other topics were firewood production, production logistics and wood fuel resources. For production of fuel chips from logging residues, a new chipper truck, MOHA-SISU, was introduced. The new machine gives a new logistic solution resulting in high productivity and reasonable operating costs. In Mikkeli region three years of active work promoted the usage of wood fuel in a district power plant to the level of over 110 000 m{sup 3} of fuel chips. The production costs tend to be a little high in average, and the production chain still needs to be improved

Bioenergy Research Programme, Yearbook 1995. Production of wood fuels; Bioenergian tutkimusohjelma, vuosikirja 1995. Puupolttoaineen tuotantotekniikka

Energy Technology Data Exchange (ETDEWEB)

Alakangas, E. [ed.

1996-12-31

Bioenergy Research Programme is one of the energy technology research programmes of the Technology Development Center TEKES. The aim of the Bioenergy Research Programme is to increase, by using technical research and development, the economically profitable and environmentally sound utilisation of bioenergy, to improve the competitiveness of present peat and wood fuels, and to develop new competitive fuels and equipment related to bioenergy. The funding for 1995 was nearly 52 million FIM and the number of projects 66. The main goal of the wood fuels research area is to develop new production methods in order to decrease the production costs to the level of imported fuels. The total potential of the wood fuel use should be at least 1.0 million toe/a (5.5 million m{sup 3}). During the year 1995 There were over 30 projects concerning the production of wood derived fuels going on. Nearly half of them focused on integrated production of pulp wood and wood fuel. About ten projects was carried out to promote the wood fuel production from logging residues. Other topics were firewood production, production logistics and wood fuel resources. For production of fuel chips from logging residues, a new chipper truck, MOHA-SISU, was introduced. The new machine gives a new logistic solution resulting in high productivity and reasonable operating costs. In Mikkeli region three years of active work promoted the usage of wood fuel in a district power plant to the level of over 110 000 m{sup 3} of fuel chips. The production costs tend to be a little high in average, and the production chain still needs to be improved

Preliminary study about refining wood fuel with torrefaction; Esiselvitys puupolttoaineen jalostamisesta torrefiointitekniikalla

Energy Technology Data Exchange (ETDEWEB)

Haemaelaeinen, E.; Heinimoe, J.

2006-07-01

The EU has started to reduce greenhouse gases which are the result of using fossil fuels. One way to do this is emission trade. There are plans to generate biofuels to replace non-renewable fuels. These biofuels can be processed with the old equipment in power plants. The advantage of biofuels is that their emission factor of carbon dioxide is agreed to be zero because wood consumes the same amount of carbon dioxide while it grows as it releases in combustion. One of these refined biofuels is torrefied wood. Its characteristics mostly correspond to coal, and it can be used in coal-fired power plants without changing equipment. Torrefaction means, in a manner of speaking, roasting wood in 250-270 deg C in oxygen-free conditions. In this process all the water is removed, as well as some of the volatile gases. The colour of the wood changes to chocolate brown, it gets lighter, does not smoke in combustion, repels water, is pulverized easily and releases only small amounts of particulate emissions. The durability and operating properties of torrefied wood are significantly different compared to the raw material. Torrefied wood also has better properties than e.g. wood coal. Torrefaction has been studied a little, and its combustion on the power plant scale has been tested on a small scale. Torrefied material is difficult and expensive to transport because of its proper-ties, so its density must be raised for transporting, e.g. by pelleting. Torrefaction combined with pelleting is, at its best, would be a competitive alternative when biomass, substituting coal, is processed off-site and transported in bulk by sea. Based on the data collected in this preliminary study it can be estimated that producing torrefied wood fuel in Finland has technical-economical possibilities. However, the application of the torrefaction process to Finnish conditions and domestic raw material demands investment in further studies before moving on to the actual implementation phase. (orig.)

Description of pelletizing facility

Energy Technology Data Exchange (ETDEWEB)

Vojin Cokorilo; Dinko Knezevic; Vladimir Milisavljevic [University of Belgrade, Belgrade (Serbia). Faculty of Mining and Geology

2006-07-01

A lot of electrical energy in Serbia was used for heating, mainly for domestics. As it is the most expensive source for heating the government announced a National Program of Energy Efficiency with only one aim, to reduce the consumption of electric energy for the heating. One of the contributions to mentioned reduction is production of coal pellets from the fine coal and its use for domestic heating but also for heating of schools, hospitals, military barracks etc. Annual production of fine coal in Serbia is 300,000 tons. The stacks of fine coal present difficulties at each deep mine because of environmental pollution, spontaneous combustion, low price, smaller market etc. To overcome the difficulties and to give the contribution to National Program of Energy Efficiency researchers from the Department of Mining Engineering, the University of Belgrade designed and realized the project of fine coal pelletizing. This paper describes technical aspect of this project. Using a CPM machine Model 7900, a laboratory facility, then a semi-industrial pelletizing facility followed by an industrial facility was set up and produced good quality pellets. The plant comprised a coal fines hopper, conveyor belt, hopper for screw conveyor, screw conveyor, continuous mixer conditioner, binder reservoir, pump and pipelines, pellet mill, product conveyor belt and product hopper. 4 refs., 3 figs., 1 tab.

X-ray investigations of lead shot pellets in the tissues of various species of birds found dead in Northern Germany

International Nuclear Information System (INIS)

Averbeck, C.; Kempen, E.; Petermann, S.; Prueter, J.; Vaur, G.; Visse, C.

1990-01-01

Within the period 1985-1988 467 specimens of dead or moribund birds including 51 species were collected in northern Germany, and x-rayed to ascertain lead pellet damage. In 15.8% of the cases evidence of lead bullets was found in the tissues. In over 80% of the cases lead pellets were found, and in 11 (14.9%) of the animals air rifle ammunition was discovered. Along with wood cock, greylag geese, and eider ducks several species of sea gulls were especially affected. The exact causes of death of the lead damaged birds could usually not be determined. The problems with lead pellet ammunition are presented and a legally designated maximum shooting distance is recommended. The replacement of lead pellets with small caliber ammunition for hunting from blinds is also discussed. Bullets are considered more effective for the hunting of knob-billed swans

Neutron absorber pellets

International Nuclear Information System (INIS)

Radford, K.C.

1983-01-01

An annular burnable poison pellet of aluminium oxide - boron carbide (Al 2 O 3 - B 4 C) adapted for positioning in the annular space of concentrically disposed zircaloy tubes. Each tubular pellet is fabricated from Al 2 O 3 powders of moderate sintering activity which serves as a matrix for B 4 C medium size particle distribution. Special pellet moisture controls are incorporated in the pellet for moisture stability and the pellet is sintered in the temperature range of 1630 deg to 1650 deg C. This method of fabrication produces a pellet about 2 inch long with a wall thickness of from 0.020 inch to 0.040 inch. Fabricating each pellet to about 70% theoretical density gives an optimum compromise between fabricability, microstructure, strength and moisture absorption. (author)

Rates of wood and dung disintegration in arid South African ...

African Journals Online (AJOL)

Dead shrubs lying on the soil surface in an arid shrubland in the southern Karoo have half-lives of 9 to 18 years depending on wood density which varies among species. Dung pellets of sheep and springbok can remain intact on the soil surface in Karoo shrubland and desert grassland for five years or more. Highlights the ...

Fish pelleting

African Journals Online (AJOL)

PUBLICATIONS1

fish meal pelletizing machine utilized 4kg of ingredients to produce 3.77kg pellets at an effi- ciency of .... Design and fabrication of fish meal pellet processing machine ... 53 ... horsepower for effective torque application on .... two edges were tacked with a spot weld to hold ... then welded on to the shaft making sure that the.

The US pellet market

International Nuclear Information System (INIS)

Elliot, S.

2007-01-01

Bear Mountain is the largest producer of pellets, firelogs, animal beddings, and barbecue pellets in Western United States. The company's branded products are sold directly to more than 400 retail dealers. This presentation included a series of graphs depicting Bear Mountain's USA pellet sales in tons from 2002 to 2007; truckloads to various distribution areas; pellet stoves and insert units shipped from 1998 to 2006; and hearth appliance shipments from 1998 to 2006. It was noted that in the United States, 98 per cent of the pellets sold come in 40 pound bags and are delivered to retailers by truck. Space is needed for inventory purposes, as each customer may use 2 to 4 tons. The pellets are used in small ash capacity room heaters. The pellet producers buy sawdust from area mills. It was noted that the soft housing market combined with competition for pulp and paper has pinched the supply of pellets. Pellets were in short supply in the west coast during the winter of 2006-2007 and in eastern United States during the winters of 2004-2005 and 2005-2006, indicating that summer production of pellets is required in order to meet winter demand. The key demand factors for pellets include stove sales; pellet pricing; pricing of other fuels; and, weather. The key supply factors for pellets include availability of sawdust; logistics; competition; and cost. The greatest challenge facing pellet producers is the high cost of freight. It was concluded that 2008 will be another year of uncertainty for pellet producers, due to the abundant supply of pellets in the east and midwest, and stabilized alternative fuel pricing. tabs., figs

Production and ejection of solid hydrogen-isotope pellet (single pellet)

International Nuclear Information System (INIS)

Kasai, Satoshi; Hasegawa, Koichi; Miura, Yukitoshi; Ishibori, Ikuo

1986-03-01

The pneumatic gun type pellet injector (single pellet) has been constructed, which is basic type used at ORNL. The pellet in the carrier is 1.65 mm in diameter and 1.65 mm in length, and another is 1 mmD x 1 mmL. Hydrogen pellet velocity of about 900 m/s was observed at propellant gas (He) pressure of 14 kg/cm 2 . In the injection experiment into a plasma, typical velocity is 714 ∼ 833 m/s. These values are 80 ∼ 95 % of velocity calculated from the ideal gun model. The ejected pellet size is 71 ∼ 90 % of the hole size in the carrier disk (1.65 mmD x 1.65 mmL) and 46 ∼ 56 % (1 mmD x 1 mmL). The spread in the pellet trajectories is about 26 mm in diameter at a plasma center. (author)

Fuel Pellets Production from Biodiesel Waste

Directory of Open Access Journals (Sweden)

Kawalin Chaiyaomporn

2010-01-01

Full Text Available This research palm fiber and palm shell were used as raw materials to produce pelletised fuel, and waste glycerol were used as adhesive to reduce biodiesel production waste. The aim of this research is to find optimum ratio of raw material (ratio of palm fiber and palm shell, raw material size distribution, adhesive temperature, and ratio of ingredients (ratio of raw material, waste glycerol, and water. The optimum ratio of pelletized fuel made only by palm fiber was 50:10:40; palm fiber, water, and waste glycerol respectively. In the best practice condition; particle size was smaller than 2 mm, adhesive glycerol was heated. From the explained optimum ratio and ingredient, pelletizing ratio was 62.6%, specific density was 982.2 kg/m3, heating value was 22.5 MJ/kg, moisture content was 5.9194%, volatile matter was 88.2573%, fix carbon content was 1.5894%, and ash content was 4.2339% which was higher than the standard. Mixing palm shell into palm fiber raw material reduced ash content of the pellets. The optimum raw material ratio, which minimizes ash content, was 80 to 20 palm fiber and palm shell respectively. Adding palm shell reduced ash content to be 2.5247% which was higher than pelletized fuel standard but followed cubed fuel standard. At this raw material ratio, pelletizing ratio was 70.5%, specific density was 774.8 kg/m3, heating value was 19.71 MJ/kg, moisture content was 9.8137%, volatile matter was 86.2259%, fix carbon content was 1.4356%, and compressive force was 4.83 N. Pelletized fuel cost at optimum condition was 1.14 baht/kg.

Development of railgun pellet injector for nuclear fusion fueling

International Nuclear Information System (INIS)

Azuma, Kingo; Oda, Yasushi; Onozuka, Masanori.

1996-01-01

Recent fusion plasmas have become larger as fusion research progresses. This requires high-velocity solid-hydrogen pellet injection that is the most efficient fueling method. The application of the electro-magnetic railgun system for pellet injection is one of the most feasible technologies for accelerating a pellet to a high speed. The system consists of a pneumatic pre-accelerator for the first acceleration stage and a railgun for the second stage. The railgun is operated by a low voltage discharged from a pulse-forming-network power supply to accelerate a plasma armature between the rail electrodes. The plasma is induced by high-power laser beam irradiation. The highest velocity of a solid-hydrogen pellet obtained using the railgun was 2.6 km/s. This velocity is higher than the maximum pellet velocity of 2.3 km/s achieved by MHI's pneumatic pellet injector. It was also found that the pellet velocity could be controlled easily using railgun pellet injection. (author)

Development of railgun pellet injector for nuclear fusion fueling

Energy Technology Data Exchange (ETDEWEB)

Azuma, Kingo [Mitsubishi Heavy Industries Ltd., Takasago, Hyogo Takasago Research and Development Center (Japan); Oda, Yasushi; Onozuka, Masanori

1996-03-01

Recent fusion plasmas have become larger as fusion research progresses. This requires high-velocity solid-hydrogen pellet injection that is the most efficient fueling method. The application of the electro-magnetic railgun system for pellet injection is one of the most feasible technologies for accelerating a pellet to a high speed. The system consists of a pneumatic pre-accelerator for the first acceleration stage and a railgun for the second stage. The railgun is operated by a low voltage discharged from a pulse-forming-network power supply to accelerate a plasma armature between the rail electrodes. The plasma is induced by high-power laser beam irradiation. The highest velocity of a solid-hydrogen pellet obtained using the railgun was 2.6 km/s. This velocity is higher than the maximum pellet velocity of 2.3 km/s achieved by MHI`s pneumatic pellet injector. It was also found that the pellet velocity could be controlled easily using railgun pellet injection. (author).

URBAN WOOD/COAL CO-FIRING IN THE NIOSH BOILER PLANT

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb Jr.

2005-02-10

gasification project at its site. Throughout much of this total project the Principal Investigator has counseled two small businesses in developing a waxed cardboard pellet business. A recent test burn of this biofuel appears successful and a purchase contract is anticipated soon. During the past two months a major tree-trimming firm has shown an active interest in entering the wood-chip fuel market in the Pittsburgh area and has contacted the NBP, among others, as potential customers. The NBP superintendent is currently in discussion with the facilities management of the Bruceton Research Center about resuming their interest in cofiring this renewable fuel to the stoker there.

Axially alignable nuclear fuel pellets

International Nuclear Information System (INIS)

Johansson, E.B.; Klahn, D.H.; Marlowe, M.O.

1978-01-01

An axially alignable nuclear fuel pellet of the type stacked in end-to-end relationship within a tubular cladding is described. Fuel cladding failures can occur at pellet interface locations due to mechanical interaction between misaligned fuel pellets and the cladding. Mechanical interaction between the cladding and the fuel pellets loads the cladding and causes increased cladding stresses. Nuclear fuel pellets are provided with an end structure that increases plastic deformation of the pellets at the interface between pellets so that lower alignment forces are required to straighten axially misaligned pellets. Plastic deformation of the pellet ends results in less interactions beween the cladding and the fuel pellets and significantly lowers cladding stresses. The geometry of pellets constructed according to the invention also reduces alignment forces required to straighten fuel pellets that are tilted within the cladding. Plastic deformation of the pellets at the pellet interfaces is increased by providing pellets with at least one end face having a centrally-disposed raised area of convex shape so that the mean temperature and shear stress of the contact area is higher than that of prior art pellets

Use of residual wood in the cement manufacturing process

International Nuclear Information System (INIS)

Gue, R.

2005-01-01

This PowerPoint presentation discussed the use of wood residuals in the cement manufacturing process. An outline of the cement manufacturing process was presented. Raw materials are combined in exact proportions to create a chemically correct mix, which is then pulverized in a mill. The mix is then burned in a kiln. The end product is cooled to form the pellet sized material known as clinker, which is then milled to form cement. The combustion and destruction characteristics of a cement kiln were presented. Modern cement kilns require approximately 3.2 Gj of energy to produce one tonne of cement. It was noted that wood residuals do not contain halogens, sulfur or other materials detrimental to the cement manufacturing process. Possible injection points for kilns were presented. Various studies have shown that wood residuals can be safely used as a fuel in the manufacture of cement. Environmental benefits derived from using wood included the complete destruction of organic portions, and the fact that residual ash becomes an indistinguishable part of the final product. It was concluded that wood residual materials are a satisfactory alternative fuel for the cement industry. tabs., figs

Analysis of existing structure and emissions of wood combustion plants for the production of heat and electricity in Bavaria; Analyse der Bestandesstruktur und der Emissionen von Holzfeuerungsanlagen zur Erzeugung von Waerme und Strom in Bayern.

Energy Technology Data Exchange (ETDEWEB)

Joa, Bettina

2014-07-01

This work deals with the detailed analysis of the existing structure of all Bavarian wood burning plants for the generation of heat and electricity as well as the determination of the resulting emission emissions in 2013. The number of wood burning plants in the single-chamber fireplaces, wood central heating and wood-fired heating plants which are in operation in the year 2013 were determined, and how many plants are existing in the various areas like pellet stoves, traditional ovens, wood-burning fireplace, pellet central heating systems, wood chips central heating systems, fire-wood central heating systems, wood combined heat and power plant (electricity and heat) and wood power plants (heat). In addition, the regional distribution of the wood burning plants in the Bavarian governmental districts is investigated as well as the type and amount of energy produced by them (heat, electricity). [German] Diese Arbeit behandelt die detaillierte Analyse der Bestandesstruktur saemtlicher bayerischer Holzfeuerungsanlagen zur Erzeugung von Waerme und Strom sowie die Ermittlung des dabei entstehenden Emissionsausstosses im Jahr 2013. Dabei wurde ermittelt wie viele Holzfeuerungsanlagen in den Segmenten Einzelraumfeuerstaetten, Holz-Zentralheizungen und Holzheiz(kraft)werke im Jahr 2013 in Bayern in Betrieb sind und wie viele Anlagen es in den einzelnen Bereichen Pelletoefen, traditionelle Oefen, Kaminoefen, Heizkamine, offene Kamine, Kacheloefen, Pellet-Zentralheizungen, Hackschnitzel-Zentralheizungen, Scheitholz-Zentralheizungen, Holzheizkraftwerke (Waerme und Strom), Holzheizwerke (Waerme) sowie Holzkraftwerke (Strom) gibt. Des Weiteren wird die regionale Verteilung der Holzfeuerungsanlagen in den bayerischen Regierungsbezirken erforscht sowie die durch sie produzierte Art und Menge an Energie (Waerme, Strom).

Fuel pellet

International Nuclear Information System (INIS)

Hayashi, K.

1980-01-01

Fuel pellet for insertion into a cladding tube in order to form a fuel element or a fuel rod. The fuel pellet has got a belt-like projection around its essentially cylindrical lateral circumferential surface. The upper and lower edges in vertical direction of this belt-like projection are wave-shaped. The projection is made of the same material as the bulk pellet. Both are made in one piece. (orig.) [de

46 CFR 148.04-21 - Coconut meal pellets (also known as copra pellets).

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Coconut meal pellets (also known as copra pellets). 148.04-21 Section 148.04-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS... § 148.04-21 Coconut meal pellets (also known as copra pellets). (a) Coconut meal pellets; (1) Must...

[Quantification of Wood Flour and Polypropylene in Chinese Fir/Polypropylene Composites by FTIR].

Science.gov (United States)

Lao, Wan-li; Li, Gai-yun; Zhou, Qun; Qin, Te-fu

2015-06-01

The ratio of wood and plastic in Wood Plastic Composites (WPCss) influences quality and price, but traditional thermochemical methods cannot rapidly and accurately quantify the ratio of wood/PP in WPCss. This paper was addressed to investigate the feasibility of quantifying the wood flour content and plastic content in WPCss by Fourier Transform Infrared (FTIR) spectroscopy. With Chinese fir, polypropylene (PP) and other additives as raw materials, 13 WPCs samples with different wood flour contents, ranging from 9.8% to 61.5%, were prepared by modifying wood flour, mixing materials and extrusion pelletizing. The samples were analyzed by FTIR with the KBr pellets technique. The absorption peaks of WPCss at 1059, 1 033 and 1 740 cm(-1) are considered as characteristic of Chinese fir, and the absorption peaks at 1 377, 2 839 and 841 cm(-1) are typical of PP by comparing the spectra of WPCss with that of Chinese fir, PP and other additives. The relationship between the wood flour content, PP content in WPCss and their characteristic IR peaks height ratio was established. The results show that there is a strong linear correlation between the wood flour content in WPCss and I1 059/l 1 377/I1 033, /I1377, R2 are 0.992 and 0.993 respectively; there is a high linear correlation between the PP content in WPCss and I1 377/I1 740, I2 839 /I1 740 R2 are 0.985 and 0.981, respectively. Quantitative methods of the wood flour content and PP content in WPCss by FTIR were developed, the predictive equations of the wood flour content in WPCss are y = 53.297x-9. 107 and y = 55.922x-10.238, the predictive equations of the PP content in WPCss are y = 6.828 5x+5.403 6 and y = 8.719 7x+3.295 8. The results of the accuracy test and precision test show that the method has strong repeatability and high accuracy. The average prediction relative deviations of the wood flour content and PP content in WPCss are about 5%. The prediction accuracy has been improved remarkably, compared to

Motivation for hay: effects of a pelleted diet on behavior and physiology of horses.

Science.gov (United States)

Elia, Jamie B; Erb, Hollis N; Houpt, Katherine Albro

2010-12-02

The natural diet of free-ranging horses is grass, which is typically high in fiber and calorically dilute, however diets for high performance domestic horses are often low in fiber and calorically dense. The aim of the study was to determine the motivation of horses for hay when fed a low roughage diet. Their motivation could be used to determine if low roughage diets compromise the welfare of horses. Eight mares were fed two different diets in counterbalanced order: ad libitum orchard grass hay; a complete pelleted feed (pellets). Each trial lasted three weeks, with a one-week transition period between diets. To determine the motivation of horses for fiber they were taught to press a panel to obtain a food reward. The fixed ratio (FR) was increased using a progressive ratio ((1,2,4,7,11…) technique. When fed pellets, the horses worked for a median FR of 1 (Range=1-497) to attain pellets, and when fed hay, they worked for a median FR of 25.5 (4-497) to attain pellets. When fed hay, the horses worked for a median FR of 0 (0-0) to attain hay, and when fed pellets, they worked for a FR of 13 (2-79) to attain hay. These results indicate a greater motivation for hay, a high fiber diet, when fed a low fiber diet. The horses spent 10 (5-19.4)% of their time during a 24-hour period eating pellets compared to 61.5 (29-76) % of their time eating hay. Horses spent 58% of their time standing when fed the pellets and only 37% of their time standing when fed hay. Searching behavior (i.e. sifting through wood shaving bedding for food particles) took up 11.5 (1.4-32) % of the horse's day when fed pellets, but only 1.2 (0-3.5) % of the daily time budget when fed hay. Horses chew more times when eating a hay diet (43,476chews/day) than when eating a pellet diet (10,036chews/day). Fecal pH was lower in horses fed the pelleted diet. Copyright © 2010 Elsevier Inc. All rights reserved.

Lithium pellet production (LiPP): A device for the production of small spheres of lithium

Science.gov (United States)

Fiflis, P.; Andrucyzk, D.; Roquemore, A. L.; McGuire, M.; Curreli, D.; Ruzic, D. N.

2013-06-01

With lithium as a fusion material gaining popularity, a method for producing lithium pellets relatively quickly has been developed for NSTX. The Lithium Pellet Production device is based on an injector with a sub-millimeter diameter orifice and relies on a jet of liquid lithium breaking apart into small spheres via the Plateau-Rayleigh instability. A prototype device is presented in this paper and for a pressure difference of ΔP = 5 Torr, spheres with diameters between 0.91 < D < 1.37 mm have been produced with an average diameter of D = 1.14 mm, which agrees with the developed theory. Successive tests performed at Princeton Plasma Physics Laboratory with Wood's metal have confirmed the dependence of sphere diameter on pressure difference as predicted.

Monitoring and data acquisition of the high speed hydrogen pellet in SPINS

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, Samiran Shanti, E-mail: samiran@ipr.res.in; Mishra, Jyotishankar; Gangradey, Ranjana; Dutta, Pramit; Rastogi, Naveen; Panchal, Paresh; Nayak, Pratik; Agarwal, Jyoti; Bairagi, Pawan; Patel, Haresh; Sharma, Hardik

2016-11-15

Highlights: • Pellet INjector System with monitoring and data acquisition is described. • A high speed camera was used to view pellet size, and its flight trajectory. • PXI based high speed control system is used data acquisition. • Pellets of length 2–4.8 mm and speed 250–750 m/s were obtained. - Abstract: Injection of solid hydrogen pellets is an efficient way of replenishing the spent fuel in high temperature plasmas. Aiming that, a Single Pellet INjector System (SPINS) is developed at Institute for Plasma Research (IPR), India, to initiate pellet injection related research in SST-1. The pellet injector is controlled by a PXI system based data acquisition and control (DAC) system for pellet formation, precise firing control, data collection and diagnostics. The velocity of high speed moving pellets is estimated by using two sets of light gate diagnostic. Apart from light gate, a fast framing camera is used to measure the pellet size and its speed. The pellet images are captured at a frame rate of ∼200,000 frames per second at (128 × 64) pixel resolution with an exposure time of 1 μs. Using these diagnostic, various cylindrical pellets of length ranging from 2 to 4.8 mm and speed 250–750 m/s were successfully obtained. This paper describes the control and data acquisition system of SPINS, the techniques for measurement of pellet velocity and capturing images of high speed moving pellet.

Development of a pellet cutting and loading device for the JT-60 repetitive pellet injector

International Nuclear Information System (INIS)

Hiratsuka, Hajime; Ichige, Hisashi; Kizu, Kaname; Iwahashi, Takaaki; Honda, Masao

2001-03-01

In JT-60, a pellet injector that repetitively injects deuterium pellets is under development to supply fuel to high temperature plasmas and sustain high-density plasmas. The pellet injector generates cubic pellets and accelerates them with a straight-arm rotor by centrifugal force. In this acceleration method, it is important to supply pellets reliably and stably, to prevent pellet orbits from disordering and to stabilize the launching direction. To achieve higher performance of the injector, a pellet cutting and loading device that cuts a deuterium ice rod into cubic pellets and loads them to the pellet injector successively and stably has been developed. The pellet cutting and loading device can cut a deuterium ice rod produced at low temperature of -8 Pam 3 /s, cutting time of <3 ms, cutting frequency of 1-20 Hz and cutter stroke of 2.5 mm were confirmed in the device test. In the operation test after assembling this device to the centrifugal pellet injector, the operational performance of pellet injection frequency of ∼10 Hz, pellet speed of ∼690 m/s and pellet injection duration time of ∼3.5 s was achieved. Thus, the development of the pellet cutting and loading device contributed to the upgrade of the JT-60 pellet injector. (author)

Advances in the study of mechanical properties and constitutive law in the field of wood research

Science.gov (United States)

Zhao, S.; Zhao, J. X.; Han, G. Z.

2016-07-01

This paper presents an overview of mechanical properties and constitutive law for wood. Current research on the mechanical properties of wood have mostly focused on density, grain, moisture, and other natural factors. It has been established that high density, dense grain, and high moisture lead to higher strength. In most literature, wood has been regarded as an anisotropic material because of its fiber. A microscopic view is used in research of wood today, in this way, which has allowed for clear observation of anisotropy. In general, wood has higher strength under a dynamic load, and no densification. The constitutive model is the basis of numerical analysis. An anisotropic model of porous and composite materials has been used for wood, but results were poor, and new constitutions have been introduced. According to the literature, there is no single theory that is widely accepted for the dynamic load. Research has shown that grain and moisture are key factors in wood strength, but there has not been enough study on dynamic loads so far. Hill law has been the most common method of simulation. Models that consider high strain rate are attracting more and more attention.

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in beached plastic pellets from Mumbai coast, India

OpenAIRE

HB Jayasiri; CS Purushothaman; V Vennila

2014-01-01

PAHs are a class of ubiquitous pollutants which consist of two or more fused benzene rings in various arrangements. A number of PAH compounds are known carcinogens and bioaccumulate and biomagnify. These compounds originate naturally as well as anthropogenically through oil spills, incineration of waste and combustion of fossil fuels and wood. The environmental consequence of Plastic pellets is the sorption organic pollutants on their surface from the sea surface microlayer (SML) where the hy...

Occurrence of polycyclic aromatic hydrocarbons (PAHs in beached plastic pellets from Mumbai coast, India

Directory of Open Access Journals (Sweden)

HB Jayasiri

2014-06-01

Full Text Available PAHs are a class of ubiquitous pollutants which consist of two or more fused benzene rings in various arrangements. A number of PAH compounds are known carcinogens and bioaccumulate and biomagnify. These compounds originate naturally as well as anthropogenically through oil spills, incineration of waste and combustion of fossil fuels and wood. The environmental consequence of Plastic pellets is the sorption organic pollutants on their surface from the sea surface microlayer (SML where the hydrophobic contaminants are known to be enriched. The plastic pellets were collected along the recent high tide line from four beaches of Mumbai coast bimonthly during May 2011 - March 2012. A total of 72 pools of plastic pellets were extracted, fractionated and analysed by Gas Chromatograph coupled to a mass spectrometer to evaluate the extent and sources of 16 PAHs. The mean ΣPAH concentration in pellets was 9202.30±114.89 ng g-1 with a wide range (35.4-46191.58 ng g-1. The concentration of fluorene was found to be the highest (1606.30±251.54 ng g-1 followed by anthracene, chrysene and phenanthrene. The ΣPAH concentration was significantly varied among months and there was no significant difference among sites at  p=0.05. The 2-3 aromatic ring compounds accounted for 60% of the total PAHs in pellets of Mumbai coast while 4 rings and 5-6 rings compounds accounted for 26 and 14%, respectively. The ratio of low and high molecular weight PAHs indicated that the contamination by petrogenic sources was predominant over the pyrogenic ones in plastic pellets suggesting oil pollution in coastal area of Mumbai.Keywords: plastic pellets, PAHs, Mumbai, sources

Emission of PCDD/F, PCB, and HCB from combustion of firewood and pellets in residential stoves and boilers.

Science.gov (United States)

Hedman, Björn; Naslund, Morgan; Marklund, Stellan

2006-08-15

To assess potential emissions of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) from residential combustion of biofuels, experiments were performed in which various types of pellets and firewood were combusted in four types of stoves and boilers, with both full and reduced rates of air supply. Intermittent combustion of wood pellets resulted in emissions of 11 ng-(WHO-TEQ)/kg combusted fuel (dry weight). A modern, environmentally certified boiler yielded somewhat lower emissions of PCCD/F and PCB than a wood stove. Both gave <0.1 ng(WHO-TEQ)/m3n (1.3-6.5 ng(WHO-TEQ)/kg) and considerably lower emissions than an old boiler (7.0-13 ng(WHO-TEQ)/kg). No positive effect on emissions could be observed in full air combustion (simulating the use of a heat storage tank) compared to combustion with reduced air. Two of the wood combustion experiments included paper and plastic waste fuels. Chlorine-containing plastic waste gave rise to high emissions: ca. 310 ng(WHO-TEQ)/ kg over the whole combustion cycle. The homologue profiles of PCDD/Fs show characteristic differences between ashes and flue gas from combustions with different levels of air supply. These differences do not, however, seem to have any correlation to the relative amount of toxic congeners.

Differences between co-cultures and monocultures in testing the toxicity of particulate matter derived from log wood and pellet combustion

Science.gov (United States)

Happo, Mikko S.; Rönkkö, Teemu J.; Orasche, Jürgen; Jokiniemi, Jorma; Kortelainen, Miika; Tissari, Jarkko; Zimmermann, Ralf; Hirvonen, Maija-Riitta; Jalava, Pasi I.

2018-01-01

Background In vitro studies with monocultures of human alveolar cells shed deeper knowledge on the cellular mechanisms by which particulate matter (PM) causes toxicity, but cannot account for mitigating or aggravating effects of cell-cell interactions on PM toxicity. Methods We assessed inflammation, oxidative stress as well as cytotoxic and genotoxic effects induced by PM from the combustion of different types of wood logs and softwood pellets in three cell culture setups: two monocultures of either human macrophage-like cells or human alveolar epithelial cells, and a co-culture of these two cell lines. The adverse effects of the PM samples were compared between these setups. Results We detected clear differences in the endpoints between the mono- and co-cultures. Inflammatory responses were more diverse in the macrophage monoculture and the co-culture compared to the epithelial cells where only an increase of IL-8 was detected. The production of reactive oxygen species was the highest in epithelial cells and macrophages seemed to have protective effects against oxidative stress from the PM samples. With no metabolically active cells at the highest doses, the cytotoxic effects of the PM samples from the wood log combustion were far more pronounced in the macrophages and the co-culture than in the epithelial cells. All samples caused DNA damage in macrophages, whereas only beech and spruce log combustion samples caused DNA damage in epithelial cells. The organic content of the samples was mainly associated with cytotoxicity and DNA damage, while the metal content of the samples correlated with the induction of inflammatory responses. Conclusions All of the tested PM samples induce adverse effects and the chemical composition of the samples determines which pathway of toxicity is induced. In vitro testing of the toxicity of combustion-derived PM in monocultures of one cell line, however, is inadequate to account for all the possible pathways of toxicity. PMID

ORNL pellet acceleration program

International Nuclear Information System (INIS)

Foster, C.A.; Milora, S.L.

1978-01-01

The Oak Ridge National Laboratory (ORNL) pellet fueling program is centered around developing equipment to accelerate large pellets of solidified hydrogen to high speeds. This equipment will be used to experimentally determine pellet-plasma interaction physics on contemporary tokamaks. The pellet experiments performed on the Oak Ridge Tokamak (ORMAK) indicated that much larger, faster pellets would be advantageous. In order to produce and accelerate pellets of the order of 1 to 6 mm in diameter, two apparatuses have been designed and are being constructed. The first will make H 2 pellets by extruding a filament of hydrogen and mechanically chopping it into pellets. The pellets formed will be mechanically accelerated with a high speed arbor to a speed of 950 m/sec. This technique may be extended to speeds up to 5000 m/sec, which makes it a prime candidate for a reactor fueling device. In the second technique, a hydrogen pellet will be formed, loaded into a miniature rifle, and accelerated by means of high pressure hydrogen gas. This technique should be capable of speeds of the order of 1000 m/sec. While this technique does not offer the high performance of the mechanical accelerator, its relative simplicity makes it attractive for near-term experiments

Pellet injectors for JET

International Nuclear Information System (INIS)

Andelfinger, C.; Buechl, K.; Lang, R.S.; Schilling, H.B.; Ulrich, M.

1981-09-01

Pellet injection for the purpose of refuelling and diagnostic of fusion experiments is considered for the parameters of JET. The feasibility of injectors for single pellets and for quasistationary refuelling is discussed. Model calculations on pellet ablation with JET parameters show the required pellet velocity ( 3 ). For single pellet injection a light gas gun, for refuelling a centrifuge accelerator is proposed. For the latter the mechanical stress problems are discussed. Control and data acquisition systems are outlined. (orig.)

Development of repetitive railgun pellet accelerator and steady-state pellet supply system

International Nuclear Information System (INIS)

Oda, Y.; Onozuka, M.; Azuma, K.; Kasai, S.; Hasegawa, K.

1995-01-01

A railgun system for repetitive high-speed pellet acceleration and steady-state pellet supply system has been developed and investigated. Using a 2m-long railgun system, the hydrogen pellet was accelerated to 2.6km/sec by the supplied energy of 1.7kJ. It is expected that the hydrogen pellet can be accelerated to 3km/sec using the present pneumatic pellet accelerator and a 2m-long augment railgun. Screw-driven hydrogen-isotope filament extruding system has been fabricated and will be tested to examine its applicability to the steady-state extrusion of the solid hydrogen-isotope filament

Development of repetitive railgun pellet accelerator and steady-state pellet supply system

Energy Technology Data Exchange (ETDEWEB)

Oda, Y.; Onozuka, M.; Azuma, K. [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Kasai, S.; Hasegawa, K. [Japan Atomic Energy Research Inst., Naka (Japan)

1995-12-31

A railgun system for repetitive high-speed pellet acceleration and steady-state pellet supply system has been developed and investigated. Using a 2m-long railgun system, the hydrogen pellet was accelerated to 2.6km/sec by the supplied energy of 1.7kJ. It is expected that the hydrogen pellet can be accelerated to 3km/sec using the present pneumatic pellet accelerator and a 2m-long augment railgun. Screw-driven hydrogen-isotope filament extruding system has been fabricated and will be tested to examine its applicability to the steady-state extrusion of the solid hydrogen-isotope filament.

Nuclear fuel pellet inspection system

International Nuclear Information System (INIS)

Ahmed, H.J.; Beatty, J.M.; Kugler, R.W.

1992-01-01

At least one axially extending linear portion of the peripheral surface of the pellet is optically sensed, a set of digital values representative of the pellet surface is generated, and the set is compared to a predetermined standard. Groups of adjacent locations on the surface of the pellet having values greater or less than the predetermined standard are identified, and the pellet is rejected, when a flawed area exceeds a predetermined size. During inspection, the pellet is moved axially through an inspection station by parallel support rolls, spaced by a distance less than the pellet diameter. The rolls are rotated upward and outward from each other, rotating the pellet, and chain dogs are positioned between the spaced rolls for engaging a pellet and moving it along the rolls. The pellet is rejected if its peripheral surface area is too great, and a reference pellet may be used. (author)

Evaluation of the coat quality of sustained release pellets by individual pellet dissolution methodology.

Science.gov (United States)

Xu, Min; Liew, Celine Valeria; Heng, Paul Wan Sia

2015-01-15

This study explored the application of 400-DS dissolution apparatus 7 for individual pellet dissolution methodology by a design of experiment approach and compared its capability with that of the USP dissolution apparatus 1 and 2 for differentiating the coat quality of sustained release pellets. Drug loaded pellets were prepared by extrusion-spheronization from powder blends comprising 50%, w/w metformin, 25%, w/w microcrystalline cellulose and 25%, w/w lactose, and then coated with ethyl cellulose to produce sustained release pellets with 8% and 10%, w/w coat weight gains. Various pellet properties were investigated, including cumulative drug release behaviours of ensemble and individual pellets. When USP dissolution apparatus 1 and 2 were used for drug release study of the sustained release pellets prepared, floating and clumping of pellets were observed and confounded the release profiles of the ensemble pellets. Hence, the release profiles obtained did not characterize the actual drug release from individual pellet and the applicability of USP dissolution apparatus 1 and 2 to evaluate the coat quality of sustained release pellets was limited. The cumulative release profile of individual pellet using the 400-DS dissolution apparatus 7 was found to be more precise at distinguishing differences in the applied coat quality. The dip speed and dip interval of the reciprocating holder were critical operational parameters of 400-DS dissolution apparatus 7 that affected the drug release rate of a sustained release pellet during the individual dissolution study. The individual dissolution methodology using the 400-DS dissolution apparatus 7 is a promising technique to evaluate the individual pellet coat quality without the influence of confounding factors such as pellet floating and clumping observed during drug release test with dissolution apparatus 1 and 2, as well as to facilitate the elucidation of the actual drug release mechanism conferred by the applied sustained

Bioenergy research programme. Yearbook 1996. Production of wood fuels; Bioenergian tutkimusohjelma. Vuosikirja 1996. Puupolttoaineiden tuotantotekniikka

Energy Technology Data Exchange (ETDEWEB)

Nikku, P [ed.

1997-12-01

The aim of the programme is to increase the use of economically profitable and environmentally sound bioenergy by improving the competitiveness of present peat and wood fuels. Research and development projects will also develop new economically competitive biofuels, new equipment and methods for production, handling and utilisation of biofuels. The total funding for 1996 was 27.3 million FIM and the number of projects 63. The number of projects concerning wood fuels production was 36. The main goals of the research are to develop new production methods for wood fuels in order to decrease the production costs to the level of imported fuels (100 km distance). The second goal is to decrease the small scale production costs by 20 % as compared with the 1992 technology level. Also, new harvesting technology and new work methods will be developed for forest owners and small-entrepreneurs in the course of the programme. Results of the projects carried out in 1996 in this programme are presented in this publication. The integrated harvesting methods, which supply both raw material to wood products industry and wood fuel for energy production, have been chosen the main research areas because they seem to be most promising. Most of the projects are focused in the wood fuel production from first thinnings and from final fellings. The projects broadly covered the research area focusing from material flows, productivity studies, basic wood properties to several case studies. The follow up project of Evaluation-drum chipper was completed with good fuel quality and productivity results. Also the large Forest Energy Project of Central Finland was completed. The project was a significant technology transfer and information dissemination project. (orig.)

PBX/TFTR pellet program PPPL

International Nuclear Information System (INIS)

Schmidt, G.

1986-01-01

Goals, current results and plans for pellet injection work for the PBX and TFTR programs are outlined. The present PBX injector is a prototype for ORNL 4 pellet condensing injectors. It has demonstrated that pellet injection on PBX can be used to increase overall density and alter the density profile. Future PBX operation requires reliable operation in deuterium and tritium, multiple pellet capability and ability to vary the size of pellets. These goals will require the construction of a new injector similar to the TFTR DPI system. It has also been demonstrated that pellets can efficiently fuel TFTR, producing a clean, high density plasma. Issues which are still outstanding include isotope exchange effects, use of different pellet sizes, optimization of pellet density perturbations and pellet penetration at high beam power

Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro

Energy Technology Data Exchange (ETDEWEB)

Uski, O., E-mail: oskari.uski@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Jalava, P.I., E-mail: pasi.jalava@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Happo, M.S., E-mail: mikko.happo@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Torvela, T., E-mail: tiina.torvela@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Leskinen, J., E-mail: jani.leskinen@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Mäki-Paakkanen, J., E-mail: jorma.maki-paakkanen@thl.fi [National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Tissari, J., E-mail: jarkko.tissari@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Sippula, O., E-mail: olli.sippula@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Lamberg, H., E-mail: heikki.lamberg@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Jokiniemi, J., E-mail: jorma.jokiniemi@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo (Finland); and others

2015-04-01

Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24 h to different doses (15, 50,150 and 300 μg ml{sup −1}) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. - Highlights: • Zinc powder was added into the

Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro

International Nuclear Information System (INIS)

Uski, O.; Jalava, P.I.; Happo, M.S.; Torvela, T.; Leskinen, J.; Mäki-Paakkanen, J.; Tissari, J.; Sippula, O.; Lamberg, H.; Jokiniemi, J.

2015-01-01

Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24 h to different doses (15, 50,150 and 300 μg ml −1 ) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. - Highlights: • Zinc powder was added into the pure

Fuel pellets from biomass - Processing, bonding, raw materials

Energy Technology Data Exchange (ETDEWEB)

Stelte, W.

2011-12-15

The present study investigates several important aspects of biomass pelletization. Seven individual studies have been conducted and linked together, in order to push forward the research frontier of biomass pelletization processes. The first study was to investigate influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding mechanisms within a biomass pellet, which indicate that different mechanisms are involved depending on biomass type and pelletizing conditions. Interpenetration of polymer chains and close intermolecular distance resulting in better secondary bonding were assumed to be the key factors for high mechanical properties of the formed pellets. The outcome of this study resulted in study four and five investigating the role of lignin glass transition for biomass pelletization. It was demonstrated that the softening temperature of lignin was dependent on species and moisture content. In typical processing conditions and at 8% (wt) moisture content, transitions were identified to be at approximately 53-63 deg. C for wheat straw and about 91 deg. C for spruce lignin. Furthermore, the effects of wheat straw extractives on the pelletizing properties and pellet stability were investigated. The sixth and seventh study applied the developed methodology to test the pelletizing properties of thermally pre-treated (torrefied) biomass from spruce and wheat straw. The results indicated that high torrefaction temperatures above 275 deg

Pellet transfer apparatus and method

International Nuclear Information System (INIS)

DiGrande, J.T.; Huggins, T.B. Sr.; Lambert, D.V.; Roberts, E.

1991-01-01

This patent describes a pellet inspection system having a station for inspecting a predetermined parameter of a pellet. It comprises means for aligning and guiding pellets in a first row to be advanced along a linear path past the pellet inspecting station and in a second row previously advanced along the linear path past the pellet inspecting station; and a transfer mechanism operable for engaging at least one of the pellets in each of the first and second rows and moving from an initial position through a forward stroke to advance the first and second rows of pellets along the liner path such that the inspecting station can inspect the preselected parameter of the pellets in the first row as they are advanced successively , the transfer mechanism being operable for disengaging the pellets and moving through a return stroke relative to the stationary advanced first and second rows of pellets back to the initial position

Recycling of wood products. Final report of the preliminary study project partly financed by the Finnish Wood Research Oy; Puutuotteiden kierraetys. Finnish Wood Research Oy:n osarahoittaman esiselvityshankkeen loppuraportti

Energy Technology Data Exchange (ETDEWEB)

Pirhonen, I.; Heraejaervi, H.; Saukkola, P.; Raety, T.; Verkasalo, E., Email: henrik.herajarvi@metla.fi

2011-07-01

The objective of this preliminary study was to clarify the present state of recycling of wood in Finland and Europe. In the work the control measures of recycling were examined. In Finland there will be a total amount of 850 000 tons of waste wood per year. Of this amount 670 000 tons is from construction and demolishing of buildings. Burning the wood to energy is technically and economically the most reasonable use of waste wood in Finland and in several other European countries where there is a long heating season. A lot of work has been done to find new ways of utilization. The objective of the European Union to increase the use of renewable natural resources in the energy production creates an additional demand to all kinds of wood, including waste wood. The waste legislation of Finland and EU is directing to recycling, not restricting it. Furthermore, the systems to try to create markets for products containing recycled materials are under development. In the future it is expected that the legislation is tightening and the burning of waste wood is no longer calculated as acceptable recycling. Other ways to utilize wood waste should then already be developed. Furthermore, the development and introduction of new recycling methods are of important significance also when marketing wood and wood products. The recycling should be taken into consideration already at the planning stage of the building

Structure change of fuel pellets

International Nuclear Information System (INIS)

Imanaka, Tetsuji

1980-01-01

The investigation of the broken pieces of fuel rods in Mihama No. 1 reactor was carried out in the Japan Atomic Energy Research Institute, and unexpectedly led to the post-irradiation tests. The investigation group of the Kyoto University Research Institute considers that the pursuit of the causes of accident by the government was insufficient, and the countermeasures are problematical, as the result of having examined various reports. In this study, the white foreign phase and swelling of cladding tubes were investigated, because these are especially important in view of the soundness of the fuel. Besides, the possibility of the oxidation of UO 2 pellets by cooling water was examined. It was found by metallographic test that the featuring phase different from UO 2 structure existed in the central part of pellets remaining in two broken fuel rod pieces. The report of JAERI judged that it is the product of solid phase reaction above a certain threshold temperature. The change of pellet structure observed in the white foreign phase and the swell of a cladding tube was caused by the oxidation of UO 2 pellets by primary coolant. The result of observation of the white foreign phase showed that it had been liquid phase at the time of the formation. From the thermodynamic examination based on oxygen potential, UO 2 is oxidized above 1100 deg C in the atmosphere of primary coolant. The liquid phase of the oxidized phase of UO 2 is formed above 1600 deg C. (Kako, I.)

Nuclear fuel pellet loading machine

International Nuclear Information System (INIS)

Dazen, J.R.; Denero, J.V.

1976-01-01

A nuclear fuel pellet loading machine is described including an inclined rack mounted on a base and having parallel spaced grooves on its upper surface arranged to support fuel rods. A fuel pellet tray is adapted to be placed on a table spaced from the rack, the tray having columns of fuel pellets which are in alignment with the open ends of fuel rods located in the rack grooves. A transition plate is mounted between the fuel rod rack and the fuel pellet tray to receive and guide the pellets into the open ends of the fuel rods. The pellets are pushed into the fuel rods by a number of mechanical fingers mounted on a motor operated block which is moved along the pellet tray length by a drive screw driven by the motor. To facilitate movement of the pellets in the fuel rods the rack is mounted on a number of spaced vibrators which vibrate the fuel rods during fuel pellet insertion. A pellet sensing device movable into an end of each fuel rod indicates to an operator when each rod has been charged with the correct number of pellets

Deuterium pellet injector gun design

International Nuclear Information System (INIS)

Lunsford, R.V.; Wysor, R.B.; Bryan, W.E.; Shipley, W.D.; Combs, S.K.; Foust, C.R.; Milora, S.L.; Fisher, P.W.

1985-01-01

The Deuterium Pellet Injector (DPI), an eight-pellet pneumatic injector, is being designed and fabricated for the Tokamak Fusion Test Reactor (TFTR). It will accelerate eight pellets, 4 by 4 mm maximum, to greater than 1500 m/s. It utilizes a unique pellet-forming mechanism, a cooled pellet storage wheel, and improved propellant gas scavenging

Conditions for new biofuel raw materials. Systems for small scale briquetting and pelletizing; Foerutsaettningar foer nya biobraensleraavaror. System foer smaaskalig brikettering och pelletering

Energy Technology Data Exchange (ETDEWEB)

Paulrud, Susanne; Holmgren, Kristina (The Swedish Environmental Research Institute Ltd., Stockholm (Sweden)); Rosenqvist, Haakan; Boerjesson, Paal (Environmental and Energy Systems Studies, Lund Inst. of Technology, Lund (Sweden))

2009-01-15

The increasing demand for biomass has driven exploitation of the most easily available and cheapest biomass resources such as sawmill waste and logging residues. More knowledge is needed about exploitation and production of potential new biomass resources, currently not used for energy production (or only to a very small extent), in order to meet the future demands from various biomass users. The project aimed to examine the conditions for use of 'new' biomass materials for heat production from technical, economic and other perspectives (price trends, attitudes etc.). More specifically, the study looked at which biomass raw materials have the best characteristics for processing into briquettes and pellets in small-scale production plants (1 000 - 10 000 tonnes fuel produced per year) situated close to the source of the raw material. The study includes a comprehensive analysis of the appropriateness of the different raw materials and a case study including cost estimates for the entire production chain for production of briquettes from reed canary grass on a chosen farm (Laattra gaard). The raw materials judged to have potential to supplement the current biomass range for heat production are willow (and to a certain extent other fast-growing hardwoods), straw and reed canary grass. In the future, other perennial grasses may be of interest. Other forestry products that may help to meet in creasing demand include logging residues, stumps and wood from thinning and precommercial thinning. The study shows that the prerequisites for processing these raw materials into briquettes and pellets in small-scale production plants are relatively good from several aspects (technology, economics, market) but are limited by the types of end user that can use that form of biomass. The study concluded that straw has a low production cost and good prerequisites as a raw material for production of fuel briquettes, fuel pellets and horse bedding pellets. However, use is

Review of pellet fueling

International Nuclear Information System (INIS)

Turnbull, R.J.

1978-01-01

Fusion reactors based on the Tokamak concept (possibly mirrors, too) will require a low energy method of fueling. Refueling by using solid pellets of hydrogen isotopes appears to be the most promising low energy technique. The main issue in assessing the feasibility of pellet fueling is the ability of the pellet to penetrate into the central region of the reactor. A review is presented of the various theories predicting the lifetime of the pellet and their regions of applicability. Among the phenomena considered are neutral ablation of the solid, ionized ablation of the solid, shielding of the pellet by neutral molecules and electrons and ions, flow of the ablation cloud, distortion of the magnetic field by the flow of an ionized ablation cloud, and charging and electrostatic shielding of the pellet. A brief summary of results of experiments done by the University of Illinois-Oak Ridge and Riso groups is presented. The results of these experiments indicate that, at least at the low temperatures and densities used, a neutral ablation-neutral shielding model is correct. Finally, since all indications are that in order for pellet fueling to be successful, high velocity pellets will be needed, a brief discussion of possible acceleration techniques is presented

Survey regarding the prices of wood fuels over the 2014 - 2015 period - Synthesis

International Nuclear Information System (INIS)

Fautrad, Alice

2015-11-01

The study conducted by CODA Strategies contains, in a first part, the synthesis and the full report of the results of a survey realized in 2015 among distributors of wood fuels for domestic, commercial, industrial and collective housing purposes. A second report presents the 2014-2015 fuel prices for commercial, industrial and collective housing markets only. This report is based on data published by the CEEB and proposes a method to estimate the cost of delivery. A third report presents the 2014-2015 results of a survey realized among distributors of wood fuels for domestic purposes only. This report also presents data regarding wood pellets price, in order to place the French market in its international context. A last report presents a French/English synthesis of the the 2014-2015 survey results

The pellet wood gasification boiler - a modern and environment-friendly alternative for energy generation in the residential section. 3. rev. ed; Scheitholzvergaserkessel - eine moderne und umweltfreundliche Alternative fuer die Energieerzeugung im haeuslichen Bereich

Energy Technology Data Exchange (ETDEWEB)

Uth, J.

2001-12-01

The decision to install a pellet wood gasification boiler is a conscious vote using renewable fuels in the residential sector. This brochure has been elaborated to facilitate interested citizens the right selection of this boilers. So an effective evaluation of the listed boiler types is possible. Text and tables are based on a manufacturers questionnaire, taking place from 1995 to September 1999respectively in October 2000 due to a fast technological development were actualized. Furthermore new sellers appeared upgrading their product spectra in the heating sector by advanced wood gasification boilers.(GL) [German] Die Entscheidung zur Installation eines Scheitholzvergaserkessels ist ein bewusstes Votum zum Einsatz eines nachwachsenden Brennstoffes im haeuslichen Bereich. Um ineressierten Buergern die Auswahl geeigneter Kessel zu erleichtern, wurde die vorliegende Broschuere ausgearbeitet. Damit ist eine effektive Beurteilung der aufgelisteten Kesseltypen moeglich. Text und Tabellen basieren auf einer Herstellerumfrage aus dem Jahr 1995, die im September 1999 bzw. im Oktober 2000 auf grund der rasanten technischen Entwicklung dieses Sektors aktualisiert werden musste. Darueber hinaus sind gaenzlich neue Anbieter aufgetreten, die ihre Produktpalette im Heizungsbereich mit modernen Scheitholzvergaserkesseln aufwerten wollen (Pflege des ''Oekoimage'').(orig/GL)

Current research in Spain on walnut for wood production

Science.gov (United States)

Neus Alet& #224; Neus NO-VALUE

2004-01-01

The Department of Mediterranean Trees at the Institut de Recerca i Tecnologia Agroalimentaries (IRTA) in Spain initiated a research program in 1993 to examine the variability among walnut species for wood production and to establish orchards with improved selections. The main objective of the programme is to obtain superior Persian walnut (Juglans regia...

Tritium pellet injector results

International Nuclear Information System (INIS)

Fisher, P.W.; Bauer, M.L.; Baylor, L.R.; Deleanu, L.E.; Fehling, D.T.; Milora, S.L.; Whitson, J.C.

1988-01-01

Injection of solid tritium pellets is considered to be the most promising way of fueling fusion reactors. The Tritium Proof-of- Principle (TPOP) experiment has demonstrated the feasibility of forming and accelerating tritium pellets. This injector is based on the pneumatic pipe-gun concept, in which pellets are formed in situ in the barrel and accelerated with high-pressure gas. This injector is ideal for tritium service because there are no moving parts inside the gun and because no excess tritium is required in the pellet production process. Removal of 3 He from tritium to prevent blocking of the cryopumping action by the noncondensible gas has been demonstrated with a cryogenic separator. Pellet velocities of 1280 m/s have been achieved for 4-mm-diam by 4-mm-long cylindrical tritium pellets with hydrogen propellant at 6.96 MPa (1000 psi). 10 refs., 10 figs

Quantification of Ash Deposit Build-up and Removal in a Straw and Wood Suspension-Fired Boiler

DEFF Research Database (Denmark)

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

2011-01-01

The aim of this study was to investigate ash deposit formation rate, heat uptake reduction and deposit removal by using advanced online ash deposition and sootblowing probes in a 350 MWth suspension­fired boiler, utilizing wood and straw pellets as fuel. The influence of fuel type (straw share...

Corrosion of Fasteners in Wood Treated with Newer Wood Preservatives

Science.gov (United States)

Samuel L. Zelinka

2013-01-01

This document compiles recent research findings related to corrosion of metals in preservative treated wood into a single report on corrosion of metals in wood. The research was conducted as part of the Research, Technology and Education portion of the National Historic Covered Bridge Preservation (NHCBP) Program administered by the Federal Highway Administration. The...

Fundamentals of Biomass pellet production

DEFF Research Database (Denmark)

Holm, Jens Kai; Henriksen, Ulrik Birk; Hustad, Johan Einar

2005-01-01

Pelletizing experiments along with modelling of the pelletizing process have been carried out with the aim of understanding the fundamental physico-chemical mechanisms that control the quality and durability of biomass pellets. A small-scale California pellet mill (25 kg/h) located with the Biomass...

Production of wood derived fuels. Review of research projects; Puupolttoaineiden tuotantotekniikka. Tutkimusalueen katsaus

Energy Technology Data Exchange (ETDEWEB)

Korpilahti, A [Metsaeteho Oy, Helsinki (Finland)

1997-12-01

The research and development work was very active on the area of wood derived fuels during the past year 1996. Totally some 40 projects were going on, and till the end of the year about 15 projects were completed. The projects broadly covered the research area focusing from material flows, productivity studies, basic wood properties to several case studies. When new production methods and machinery was introduced earlier by demonstration projects, now they were investigated by follow up projects. The economical and quality results of logging residue harvesting and comminution seem quite satisfactory, but integrated methods and production chains still need research and development. (orig.)

Modeling pellet impact drilling process

Science.gov (United States)

Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Ulyanova, O. S.

2016-03-01

The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling the process of pellet impact drilling, which creates the scientific and methodological basis for engineering design of drilling operations under different geo-technical conditions.

Mycelial pellet formation by edible ascomycete filamentous fungi, Neurospora intermedia.

Science.gov (United States)

Nair, Ramkumar B; Lennartsson, Patrik R; Taherzadeh, Mohammad J

2016-12-01

Pellet formation of filamentous fungi in submerged culture is an imperative topic of fermentation research. In this study, we report for the first time the growth of filamentous ascomycete fungus, Neurospora intermedia in its mycelial pellet form. In submerged culture, the growth morphology of the fungus was successfully manipulated into growing as pellets by modifying various cultivation conditions. Factors such as pH (2.0-10.0), agitation rate (100-150 rpm), carbon source (glucose, arabinose, sucrose, and galactose), the presence of additive agents (glycerol and calcium chloride) and trace metals were investigated for their effect on the pellet formation. Of the various factors screened, uniform pellets were formed only at pH range 3.0-4.0, signifying it as the most influential factor for N. intermedia pellet formation. The average pellet size ranged from 2.38 ± 0.12 to 2.86 ± 0.38 mm. The pellet formation remained unaffected by the inoculum type used and its size showed an inverse correlation with the agitation rate of the culture. Efficient glucose utilization was observed with fungal pellets, as opposed to the freely suspended mycelium, proving its viability for fast-fermentation processes. Scale up of the pelletization process was also carried out in bench-scale airlift and bubble column reactors (4.5 L).

Multi-shot type pellet injection device

International Nuclear Information System (INIS)

Onozuka, Masaki; Uchikawa, Takashi; Kuribayashi, Shitomi.

1988-01-01

Purpose: To inject pellets at high speed without melting or sublimating not-injected pellets even at a long pellet injection interval. Constitution: In the conventional multi-shot pellet injection device, the pellet injection interval is set depending on the plasma retention time. However, as the pellet injection interval is increased, not-injected pellets are melted or sublimated due to the introduced heat of acceleration gases supplied from an acceleration gas introduction pipe to give an effect on the dimensional shape of the pellets. In view of the above, a plurality of pellet forming and injection portions each comprising a carrier, an injection pipe and a holder are disposed independently of each other and pellets are formed and injected independently to thereby prevent the thermal effects of the acceleration gases. (Kamimura, M.)

Multi-shot type pellet injection device

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masaki; Uchikawa, Takashi; Kuribayashi, Shitomi.

1988-07-27

Purpose: To inject pellets at high speed without melting or sublimating not-injected pellets even at a long pellet injection interval. Constitution: In the conventional multi-shot pellet injection device, the pellet injection interval is set depending on the plasma retention time. However, as the pellet injection interval is increased, not-injected pellets are melted or sublimated due to the introduced heat of acceleration gases supplied from an acceleration gas introduction pipe to give an effect on the dimensional shape of the pellets. In view of the above, a plurality of pellet forming and injection portions each comprising a carrier, an injection pipe and a holder are disposed independently of each other and pellets are formed and injected independently to thereby prevent the thermal effects of the acceleration gases. (Kamimura, M.).

Pellet imaging techniques on ASDEX

International Nuclear Information System (INIS)

Wurden, G.A.; Buechl, K.; Hofmann, J.; Lang, R.; Loch, R.; Rudyj, A.; Sandmann, W.

1990-01-01

As part of a USDOE/ASDEX collaboration, a detailed examination of pellet ablation in ASDEX with a variety of diagnostics has allowed a better understanding of a number of features of hydrogen ice pellet ablation in a plasma. In particular, fast gated photos with an intensified Xybion CCD video camera allow in-situ velocity measurements of the pellet as it penetrates the plasma. With time resolution of typically 100 nanoseconds and exposures every 50 microseconds, the evolution of each pellet in a multi-pellet ASDEX tokamak plasma discharge can be followed. When the pellet cloud track has striations, the light intensity profile through the cloud is hollow (dark near the pellet), whereas at the beginning or near the end of the pellet trajectory the track is typically smooth (without striations) and has a gaussian-peaked light emission profile. New, single pellet Stark broadened D α D β , and D γ spectra, obtained with a tangentially viewing scanning mirror/spectrometer with Reticon array readout, are consistent with cloud densities of 2 x 10 17 cm -3 or higher in the regions of strongest light emission. A spatially resolved array of D α detectors shows that the light variations during the pellet ablation are not caused solely by a modulation of the incoming energy flux as the pellet crosses rational q-surfaces, but instead are a result of a dynamic, non-stationary, ablation process. 20 refs., 4 figs

Methane pellet moderator development

International Nuclear Information System (INIS)

Foster, C.A.; Schechter, D.E.; Carpenter, J.M.

2004-01-01

A methane pellet moderator assembly consisting of a pelletizer, a helium cooled sub-cooling tunnel, a liquid helium cooled cryogenic pellet storage hopper and a 1.5L moderator cell has been constructed for the purpose demonstrating a system for use in high-power spallation sources. (orig.)

Development of pellet injection systems for ITER

International Nuclear Information System (INIS)

Combs, S.K.; Gouge, M.J.; Baylor, L.R.

1995-01-01

Oak Ridge National Laboratory (ORNL) has been developing innovative pellet injection systems for plasma fueling experiments on magnetic fusion confinement devices for about 20 years. Recently, the ORNL development has focused on meeting the complex fueling needs of the International Thermonuclear Experimental Reactor (ITER). In this paper, we describe the ongoing research and development activities that will lead to a ITER prototype pellet injector test stand. The present effort addresses three main areas: (1) an improved pellet feed and delivery system for centrifuge injectors, (2) a long-pulse (up to steady-state) hydrogen extruder system, and (3) tritium extruder technology. The final prototype system must be fully tritium compatible and will be used to demonstrate the operating parameters and the reliability required for the ITER fueling application

Nuclear fuel pellet collating system and method

International Nuclear Information System (INIS)

Rieben, S.L.; Kugler, R.W.; Scherpenberg, J.J.; Wiersema, D.T.

1990-01-01

This patent describes a method of collating nuclear fuel pellets. It comprises: supporting a plurality of pellet supply trays and a plurality of pellet storage trays at a tray positioning station. Each of the supply trays containing in at least one row thereon a plurality of nuclear fuel pellets of an enrichment different from the enrichment pellets on at least some other of the supply trays; transferring one pellet supply tray from the tray positioning station and disposing the same at an input station of a pellet collating line; transferring one pellet storage tray from the tray positioning station and disposing the same at an output station of the pellet collating line; sweeping pellets in the at least one row thereof from the one pellet supply tray onto a work station of the pellet collating line located between the input and output stations thereof; measuring a desired length of pellets in the at least one row on the work station and separating the measured desired length of pellets from the remaining pellets, if any, in the row thereof; sweeping the remaining pellets, if any, in the row from the work station back onto the one pellet supply tray; transferring the one pellet supply tray and remaining pellets, if any, back to the tray positioning station; sweeping the measured desired length of pellets from the work station onto the one pellet storage tray; and transferring the one pellet storage tray and measured desired length of pellets back to the tray positioning station

Second jet workshop on pellet injection: pellet fueling program in the United States. Summary

International Nuclear Information System (INIS)

Milora, S.L.

1983-01-01

S. Milora described the US programme on pellet injection. It has four parts: (1) a confinement experimental program; (2) pellet injector development; (3) theoretical support; and (4) tritium pellet study for TFTR

Upgraded wood residue fuels 1995

International Nuclear Information System (INIS)

Vinterbaeck, J.

1995-01-01

The Swedish market for upgraded residue fuels, i.e. briquettes, pellets and wood powder, has developed considerably during the nineties. The additional costs for the upgrading processes are regained and create a surplus in other parts of the system, e.g. in the form of higher combustion efficiencies, lower investment costs for burning equipment, lower operation costs and a diminished environmental impact. All these factors put together have resulted in a rapid growth of this part of the energy sector. In 1994 the production was 1.9 TWh, an increase of 37 % compared to the previous year. In the forthcoming heating season 1995/96 the production may reach 4 TWh. 57 refs, 11 figs, 6 tabs

Non_standard Wood

DEFF Research Database (Denmark)

Tamke, Martin

. Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software......, but the integration of traditional wood craft techniques. The extensive use of self adjusting, load bearing wood-wood joints contributed to ease in production and assembly of a performance based architecture....

Statistical analysis and modeling of pelletized cultivation of Mucor circinelloides for microbial lipid accumulation.

Science.gov (United States)

Xia, Chunjie; Wei, Wei; Hu, Bo

2014-04-01

Microbial oil accumulation via oleaginous fungi has some potential benefits because filamentous fungi can form pellets during cell growth and these pellets are easier to harvest from the culture broth than individual cells. This research studied the effect of various culture conditions on the pelletized cell growth of Mucor circinelloides and its lipid accumulation. The results showed that cell pelletization was positively correlated to biomass accumulation; however, pellet size was negatively correlated to the oil content of the fungal biomass, possibly due to the mass transfer barriers generated by the pellet structure. How to control the size of the pellet is the key to the success of the pelletized microbial oil accumulation process.

Pellet injector development at ORNL

International Nuclear Information System (INIS)

Milora, S.L.; Argo, B.E.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Qualls, A.L.; Schechter, D.E.; Sparks, D.O.; Tsai, C.C.; Whealton, J.H.; Wilgen, J.B.; Schmidt, G.L.

1992-01-01

Plasma fueling systems for magnetic confinement experiments are under development at Oak Ridge National Laboratory (ORNL). ORNL has recently provided a four-shot tritium pellet injector with up to 4-mm-diam capability for the Tokamak Fusion Test Reactor (TFTR). This injector, which is based on the in situ condensation technique for pellet formation, features three single-stage gas guns that have been qualified in deuterium at up to 1.7 km/s and a two-stage light gas gun driver that has been operated at 2.8-km/s pellet speeds for deep penetration in the high-temperature TFTR supershot regime. Performance improvements to the centrifugal pellet injector for the Tore Supra tokamak are being made by modifying the storage-type pellet feed system, which has been redesigned to improve the reliability of delivery of pellets and to extend operation to longer pulse durations (up to 400 pellets). Two-stage light gas guns and electron-beam (e-beam) rocket accelerators for speeds in the range from 2 to 10 km/s are also under development. A repeating, two-stage light gas gun that has been developed can accelerate low-density plastic pellets at a 1-Hz repetition rate to speeds of 3 km/s. In a collaboration with ENEA-Frascati, a test facility has been prepared to study repetitive operation of a two-stage gas gun driver equipped with an extrusion-type deuterium pellet source. Extensive testing of the e-beam accelerator has demonstrated a parametric dependence of propellant burn velocity and pellet speed, in accordance with a model derived from the neutral gas shielding theory for pellet ablation in a magnetized plasma

Pneumatic pellet injector for JET

International Nuclear Information System (INIS)

Andelfinger, C.; Buechl, K.; Jacobi, D.; Sandmann, W.; Schiedeck, J.; Schilling, H.B.; Weber, G.

1983-07-01

Pellet injection is a useful tool for plasma diagnostics of tokamaks. Pellets can be applied for investigation of particle, energy and impurity transport, fueling efficiency and magnetic surfaces. Design, operation and control of a single shot pneumatic pellet gun is described in detail including all supplies, the vacuum system and the diagnostics of the pellet. The arrangement of this injector in the torus hall and the interfaces to the JET system and CODAS are considered. A guide tube system for pellet injection is discussed but it will not be recommended for JET. (orig.)

Pellet injection in WVIIA

International Nuclear Information System (INIS)

Renner, H.; Wuersohing, E.; Weller, A.; Jaeckel, H.; Hartfuss, H.; Hacker, H.; Ringler, H.; Buechl, K.

1986-01-01

The results of pellet injection experiments in the Wendelstein VII A stellarator are presented. The injector was a single shot pneumatic gun using deuterium pellets. Experiments were carried out in both ECRH and NI plasmas. Data is shown for plasma density, energy confinement, penetration depth and pellet ablation. Results are compared to a neutral gas shielding model

Nuclear fuel pellet loading machine

International Nuclear Information System (INIS)

Kee, R.W.; Denero, J.V.

1975-01-01

An apparatus for loading nuclear fuel pellets on trays for transfer in a system is described. A conveyor supplies pellets from a source to a loading station. When the pellets reach a predetermined position at the loading station, a manual or automatically operated arm pushes the pellets into slots on a tray and this process is repeated until pellet sensing switches detect that the tray is full. Thereupon, the tray is lowered onto a belt or other type conveyor and transferred to other apparatus in the system, such as a furnace for sintering, and in some cases, reduction of UO 2 . 2 to UO 2 . The pellets are retained on the tray and subsequently loaded directly into fuel rods to be used in the reactor core. (auth)

Developments in MOX fuel pellet fabrication technology: Indian experience

International Nuclear Information System (INIS)

Kamath, H.S.; Majumdar, S.; Purusthotham, D.S.C.

1998-01-01

India is interested in mixed oxide (MOX) fuel technology for better utilisation of its nuclear fuel resources. In view of this, a programme involving MOX fuel design, fabrication and irradiation in research and power reactors has been taken up. A number of experimental irradiations in research reactors have been carried out and a few MOX assemblies of ''All Pu'' type have been loaded in our commercial BWRs at Tarapur. An island type of MOX fuel design is under study for use in PHWRs which can increase the burn-up of the fuel by more than 30% compared to natural UO 2 fuel. The MOX fuel pellet fabrication technology for the above purpose and R and D efforts in progress for achieving better fuel performance are described in the paper. The standard MOX fuel fabrication route involves mechanical mixing and milling of UO 2 and PuO 2 powders. After detailed investigations with several types of mixing and milling equipments, dry attritor milling has been found to be the most suitable for this operation. Neutron Coincident Counting (NCC) technique was found to be the most convenient and appropriate technique for quick analysis of Pu content in milled MOX powder and to know Pu mixing is homogenous or not. Both mechanical and hydraulic presses have been used for powder compaction for green pellet production although the latter has been preferred for better reproducibility. Low residue admixed lubricants have been used to facilitate easy compaction. The normal sintering temperature used in Nitrogen-Hydrogen atmosphere is between 1600 deg. C to 1700 deg. C. Low temperature sintering (LTS) using oxidative atmospheres such as carbon dioxide, Nitrogen and coarse vacuum have also been investigated on UO 2 and MOX on experimental scale and irradiation behaviour of such MOX pellets is under study. Ceramic fibre lined batch furnaces have been found to be the most suitable for MOX pellet production as they offer very good flexibility in sintering cycle, and ease of maintainability

Yearbook 1998. TULISIJA Research Programme for Wood Firing Technology; Vuosikirja - Aarsbok 1997. TULISIJA

Energy Technology Data Exchange (ETDEWEB)

Ljung, M.; Kilpinen, P. [eds.

1999-11-01

TULISIJA is the 3-year national research programme for small scale wood firing technology with the aim to assist manufacturers in their efforts to develop the most emission-free, yet efficient, wood firing equipment in the world. The following ten projects have been in progress during the year 1998: The behaviour of fuel; Computational fluid dynamics simulation of combustion in small scale wood ovens; computational fluid dynamics simulation of combustion in small scale wood ovens and modelling of emission chemistry; Modelling of heat transfer in fireplace walls and constructions; Detailed emission and temperature measurements in the TULISIJA test oven; Measurement environment for fireplace testing; Reduction of emissions from soapstone fireplaces; Development of a new modular method for fireplace manufacture; Replacement of energy intensive raw material with recycled industrial waste and further development of combustion processes in fireplaces and Instructions for dimensioning and design of fireplaces for optimum living atmosphere in residences

Fuel rod pellet loading head

International Nuclear Information System (INIS)

Howell, T.E.

1975-01-01

An assembly for loading nuclear fuel pellets into a fuel rod comprising a loading head for feeding pellets into the open end of the rod is described. The pellets rest in a perforated substantially V-shaped seat through which air may be drawn for removal of chips and dust. The rod is held in place in an adjustable notched locator which permits alignment with the pellets

Fabrication of nano-structured UO2 fuel pellets

International Nuclear Information System (INIS)

Yang, Jae Ho; Kang, Ki Won; Rhee, Young Woo; Kim, Dong Joo; Kim, Jong Heon; Kim, Keon Sik; Song, Kun Woo

2007-01-01

Nano-structured materials have received much attention for their possibility for various functional materials. Ceramics with a nano-structured grain have some special properties such as super plasticity and a low sintering temperature. To reduce the fuel cycle costs and the total mass of spent LWR fuels, it is necessary to extend the fuel discharged burn-up. In order to increase the fuel burn-up, it is important to understand the fuel property of a highly irradiated fuel pellet. Especially, research has focused on the formation of a porous and small grained microstructure in the rim area of the fuel, called High Burn-up Structure (HBS). The average grain size of HBS is about 300nm. This paper deals with the feasibility study on the fabrication of nano-structured UO 2 pellets. The nano sized UO 2 particles are prepared by a combined process of a oxidation-reducing and a mechanical milling of UO 2 powder. Nano-structured UO 2 pellets (∼300nm) with a density of ∼93%TD can be obtained by sintering nano-sized UO 2 compacts. The SEM study reveals that the microstructure of the fabricated nano-structure UO 2 pellet is similar to that of HBS. Therefore, this bulk nano-structured UO 2 pellet can be used as a reference pellet for a measurement of the physical properties of HBS

Complex geometries in wood

DEFF Research Database (Denmark)

Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

2009-01-01

The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

Review: study of single-pellet injection experiments and development of pellet injector in JFT-2M

International Nuclear Information System (INIS)

Kasai, Satoshi; Miura, Yukitoshi; Hasegawa, Kouichi; Sengoku, Seio

1987-10-01

The single pellet injector developed for JFT-2M and the improvement of plasma characteristics in the auxiliary-heated discharges by single-pellet injection are reviewed for the period 1982 - 1986. The pellet injector is a pneumatic type and the designed pellet size is 1.65 mmD x 1.65 mmL and 1 mmD x 1 mmL. The hydrogen, deuterium and mixed (H 2 + D 2 ) pellets can be produced with good reproducibility. Maximum pellet velocity is about 970 m/s (pellet is deuterium and propellant gas is hydrogen). In the pellet injection experiments into auxiliary-heated (NB, ICRF) divertor or limiter discharges, the plasma confinement time is improved by a factor of 1.4 - 1.7 compared with the confinement time in the Ohmic discharges. The achieved confinement time is longer than that on the high confinement mode (H-mode) in gas fueled discharges, although the phenomena are transient. (author)

Recent Developments Concerning Pellet Combustion Technologies - A Review of Austrian Developments

International Nuclear Information System (INIS)

Obernberger, I.; Thek, G.

2006-01-01

This paper gives an overview of recent developments concerning pellet combustion technologies in Austria. It covers basic information about the Austrian pellet market and market developments in recent years as well as about national framework conditions in Austria with regard to standards for Pellets, pellet furnaces and emission limits. A detailed overview is given of the state-of-the-art of Austrian pellet boiler technology, which is - from a technological point of view - probably the best developed market world-wide. Innovations, which have recently been developed and introduced into the market, are described. The most important innovations are new furnace developments based on CFD (Computational Fluid Dynamics) simulations, flue gas condensation systems for small-scale pellet boilers and multi-fuel concepts, where e.g. firewood and Pellets can be utilised in one boiler. Moreover, emissions from pellet furnaces are discussed and evaluated based on test stand and field measurements. In this respect, a focus is put on fine particulate emissions from pellet boilers. Finally, future developments based on ongoing research projects are described and discussed. The ongoing R and D activities focus on the further reduction of fine particulate emissions by primary and secondary measures, the utilisation of herbaceous biomass fuels and small or micro-scale CHP systems

Pellet injection into ASDEX upgrade plasmas

International Nuclear Information System (INIS)

Lang, P.T.; Zohm, H.; Buechl, K.; Fuchs, J.C.; Gehre, O.; Gruber, O.; Lang, R.S.; Mertens, V.; Neuhauser, J.; Salzmann, H.

1996-04-01

This work comprises results obtained using the new centrifuge injection system for the two first years of pellet injection experiments at Asdex Upgrade until the end of the 1995 experimental campaign. The main aim of the pellet injection investigation is to develop scenarios allowing for a more flexible plasma density control means of injection of cryogenic solid hydrogen pellets. Efforts have been made to develop scenarios allowing more flexible plasma density control by injecting cryogenic solid hydrogen pellets. While the injection of pellets during ohmic discharges was found to be most efficient and also improves the plasma performance, increasing the auxiliary heating power causes a detoriation of the pellet fuelling efficiency. A further strong reduction of the pellet fuelling efficiency by an additional process was observed for the more reactor-relevant conditions of shallow particle deposition during H-mode phases. With injection during type I ELMy H-mode phases, each pellet was found to trigger the release of an ELM and therefore cause particle losses mainly from the edge region. In the type I ELMy H-mode, only sufficient pellet penetration allowed noticeable, persistent particle deposition in the plasma by the pellets. Applying adequate pellet injection conditions and favourable scenarios using combined pellet/gas puff refuelling, significant density ramp-up to densities exceeding the empirical Greenwald limit by up to a factor of two was achieved even for strongly heated H-mode plasmas. (orig.)

Pelletizing using forest fuels and Salix as raw materials. A study of the pelletizing properties; Pelletering med skogsbraensle och Salix som raavara. En undersoekning av pelleterbarheten

Energy Technology Data Exchange (ETDEWEB)

Martinsson, Lars; Oesterberg, Stefan [Swedish National Testing and Research Inst., Boraas (Sweden)

2004-08-01

Three common forest fuels: light thinning material, cull tree and logging residues as well as energy forest fuel (Salix) has been used as fuel pellet materials. Logging residues and Salix were stacked for approximately 6 and 10 months respectively. Parameters varied for each raw material have been the moisture content and the press length of the die. These parameters have been changed to obtain best possible quality, mainly concerning mechanical durability. Pellets were also produced from bark free shavings in order to use as a reference in this study. Physical as well as chemical properties have been compared. It was comparatively easy to press logging residues and Salix into durable pellets and, even with larger press length, the production of pellets was higher than it was for the other raw materials. The density was equal for all pellets while the mechanical durability was better for all tested raw materials compared with the reference material. The fact that all raw materials besides the reference material contains bark which has an improving effect on the degree of hardness. The quality properties were mainly about the same or better for pellets made of light thinning material and cull tree respectively, compared with the reference pellets. However, the ash content was approximately twice as high compared with the reference pellets. The pellets made of logging residues and Salix respectively were of very good quality concerning duration and density but the ash content was approximately 10 times higher than in the reference pellets. Additionally, the nitrogen content was 6-9 times higher compared with the reference pellets.

Electricity savings with pellet stoves and solar heating in electrically heated houses; Elbesparing med pelletkaminer och solvaerme i direktelvaermda smaahus

Energy Technology Data Exchange (ETDEWEB)

Persson, Tomas [Hoegskolan Dalarna, Borlaenge (Sweden)

2004-07-01

The aim of this study was to investigate how electrically heated houses can be converted to using wood pellet and solar heating. There are a large number of wood pellet stoves on the market. Many stoves have a water jacket, which gives an opportunity to distribute the heat to domestic hot water and a radiator heating system. Three typical Swedish houses with electric resistance heating have been studied. Fourteen different system concepts using wood pellet stoves and solar heating systems have been evaluated. The systems and the houses have been simulated in detail using TRNSYS. The houses have been divided in up to 10 different zones and heat transfer by air circulation through doorways and open doors have been simulated. The pellet stoves were simulated using a recently developed TRNSYS component, which models the start- and stop phases, emissions and the dynamic behaviour of the stoves. The model also calculates the CO-emissions. Simulations were made with one stove without a water jacket and two stoves with different fractions of the generated heat distributed in the water circuit. Simulations show that the electricity savings using a pellet stove are greatly affected by the house plan, the system choice, if the internal doors are open or closed and the desired level of comfort. Installing a stove with a water-jacket connected to a radiator system and a hot water storage has the advantage that heat can be transferred to domestic hot water and be distributed to other rooms. Such systems lead to greater electricity savings, especially in houses having a traditional layout. It was found that not all rooms needed radiators and that it was more effective in most cases to use a stove with a higher fraction of the heat distributed by the water circuit. The economic investigation shows that installing a wood pellet stove without a water jacket gives the lowest total energy- and capital costs in the house with an open plan (for today's energy prices and the

Elemental and organic carbon in flue gas particles of various wood combustion systems

Energy Technology Data Exchange (ETDEWEB)

Gaegauf, C.; Schmid, M.; Guentert, P.

2005-12-15

The airborne particulate matter (PM) in the environment is of ever increasing concern to authorities and the public. The major fractions of particles in wood combustion processes are in the size less than 1 micron, typically in the range of 30 to 300 nm. Of specific interest is the content of the elemental carbon (EC) and organic carbon (OC) in the particles since these substances are known for its particular potential as carcinogens. Various wood combustion systems have been analysed (wood chip boiler, pellet boiler, wood log boiler, wood stove and open fire). The sampling of the particles was done by mean of a multi-stage particle sizing sampler cascade impactor. The impactor classifies the particles collected according to their size. The 7 stages classify the particles between 0.4 and 9 microns aerodynamic diameter. The analytical method for determining the content of EC and OC in the particles is based on coulometry. The coulometer measures the conductivity of CO{sub 2} released by oxidation of EC in the samples at 650 {sup o}C. The OC content is determined by pyrolysis of the particle samples in helium atmosphere.

Initial deuterium pellet experiments on FTU

International Nuclear Information System (INIS)

Snipes, J.A.

1993-01-01

Initial experiments have been performed with the Single Pellet INjector (SPIN) on FTU. SPIN is a two-stage cryogenic deuterium pellet injector capable of injection,a pellets with velocities up to 2.5 km/s. The nominal pellet mass for these experiments was approximately 1 x 10 20 atoms. These initial pellet experiments concentrated on studying pellet penetration under a variety of plasma conditions to compare with code predictions and to examine toroidal particle transport. The principal diagnostics used were two fast (∼1 μsec) photomultiplier tubes at nearly opposite toroidal locations with H α (D α ) interference filters (λ = 656 nm), a microwave cavity for pellet mass and velocity, a vertical array of soft x ray diodes without filters looking down onto the pellet, a DCN interferometer for electron density profiles, and a Michelson ECE system for electron temperature profiles. The time integral of the absolutely calibrated fast H α signal appears to give reasonable agreement with the expected pellet mass. Toroidal transport of deuterium ions from the pellet to nearly the opposite side of the tokamak agrees with calculated thermal deuterium velocities near the plasma edge. Comparison of the experimental results with code calculations using the Neutral Gas Shielding model show good agreement for the post-pellet electron temperature and density profiles and the H α profiles in some cases. Calculated penetration distances agree within 20%

Investigations of primary and secondary particulate matter of different wood combustion appliances with a high-resolution time-of-flight aerosol mass spectrometer

Directory of Open Access Journals (Sweden)

M. F. Heringa

2011-06-01

Full Text Available A series of photo-oxidation smog chamber experiments were performed to investigate the primary emissions and secondary aerosol formation from two different log wood burners and a residential pellet burner under different burning conditions: starting and flaming phase. Emissions were sampled from the chimney and injected into the smog chamber leading to primary organic aerosol (POA concentrations comparable to ambient levels. The composition of the aerosol was measured by an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS and black carbon (BC instrumentation. The primary emissions were then exposed to xenon light to initiate photo-chemistry and subsequent secondary organic aerosol (SOA production. After correcting for wall losses, the average increase in organic matter (OM concentrations by SOA formation for the starting and flaming phase experiments with the two log wood burners was found to be a factor of 4.1±1.4 after five hours of aging. No SOA formation was observed for the stable burning phase of the pellet burner. The startup emissions of the pellet burner showed an increase in OM concentration by a factor of 3.3. Including the measured SOA formation potential, average emission factors of BC+POA+SOA, calculated from CO₂ emission, were found to be in the range of 0.04 to 3.9 g/kg wood for the stable burning pellet burner and an old log wood burner during startup respectively. SOA contributed significantly to the ion C₂H₄O₂⁺ at mass to charge ratio m/z 60, a commonly used marker for primary emissions of wood burning. This contribution at m/z 60 can overcompensate for the degradation of levoglucosan leading to an overestimation of the contribution of wood burning or biomass burning to the total OM. The primary organic emissions from the three different burners showed a wide range in O:C atomic ratio (0.19−0.60 for the starting and flaming

Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

DEFF Research Database (Denmark)

Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.

2012-01-01

and a high concentration of hydrophobic waxes on its outer surface that may limit the pellet strength. The present work studies the impact of the lignin glass transition on the pelletizing properties of wheat straw. Furthermore, the effect of surface waxes on the pelletizing process and pellet strength...... are investigated by comparing wheat straw before and after organic solvent extraction. The lignin glass transition temperature for wheat straw and extracted wheat straw is determined by dynamic mechanical thermal analysis. At a moisture content of 8%, transitions are identified at 53°C and 63°C, respectively....... Pellets are pressed from wheat straw and straw where the waxes have been extracted from. Two pelletizing temperatures were chosen—one below and one above the glass transition temperature of lignin. The pellets compression strength, density, and fracture surface were compared to each other. Pellets pressed...

Environmental-performance research priorities: Wood products. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-15

This report describes a research plan to establish environmental, energy, and economic performance measures for renewable building materials, and to identify management and technology alternatives to improve environmental performance in a cost-effective manner. The research plan is designed to: (1) collect environmental and economic data on all life-cycle stages of the materials, (2) ensure that the data follows consistent definitions and collection procedures, and (3) develop analytical procedures for life-cycle analysis to address environmental performance questions. The research will be subdivided into a number of individual project modules. The five processing stages of wood used to organize the research plan are: (1) resource management and harvesting; (2) processing; (3) design and construction of structures; (4) use, maintenance, and disposal; and (5) waste recycling. Individual research module descriptions are provided in the report, as well as assessment techniques, research standards and protocol, and research management. 13 refs., 5 figs., 3 tabs.

The JET multi-pellet injector launcher

International Nuclear Information System (INIS)

Kupschus, P.; Bailey, W.; Gadeberg, M.; Hedley, L.; Twyman, P.; Szabo, T.; Evans, D.

1987-01-01

Under a collaborative agreement between the Joint European Torus JET and the United States Department of Energy US DOE, JET and Oak Ridge National Laboratory (ORNL) jointly built a multi-pellet injector for fuelling and re-fuelling of the JET plasma. A three-barrel repetitive pneumatic pellet Launcher - built by ORNL - is attached to a JET pellet launcher-machine interface (in short: Pellet Interface) which is the subject of this paper. The present Launcher-Interface combination provides deuterium or hydrogen injection at moderate pellet speeds for the next two operational periods on JET. The Pellet Interface, however, takes into account the future requirements of JET. It was designed to allow the attachment of the high speed pellet launchers now under development at JET and complies with the requirements of remote handling and tritium operation. In addition, the use of tritium pellets is being considered

Reciprocating pellet press

Science.gov (United States)

Jones, Charles W.

1981-04-07

A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

EXPERIMENTAL RESEARCH CONCERNING THE OPTIMAL DIMENSIONS OF AN ELASTIC STRUCTURE OF BEECH WOOD PARQUET

Directory of Open Access Journals (Sweden)

Olimpia-Minerva ȚURCAȘ (DIACONU

2015-12-01

Full Text Available This paper presents the results of the experimental research concerning the modulus of elasticity and the average value of the bending strength in case of beech (Fagus sylvatica L. wood. The investigations were performed according to SR EN 408-2004. The results of the research have been analysed in order to establish the variable parameters to be considered for the final experimental research focused on beech wood floor structures that meet the necessary requirements for the sports halls applications. The research presented in the paper is a part of the study theme of the Ph. D. thesis, which investigates the flooring structures able to support the requirements of sports halls activities, different from one sport to another.

Tritium pellet injector for TFTR

International Nuclear Information System (INIS)

Gouge, M.J.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foust, C.R.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Wilgen, J.B.; Schmidt, G.L.; Barnes, G.W.; Persing, R.G.

1992-01-01

The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) phase. The existing TFTR deuterium pellet injector (DPI) has been modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed to provide pellets ranging from 3.3 to 4.5 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller. The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed, and the TPI was tested at ORNL with deuterium pellet. Results of the limited testing program at ORNL are described. The TPI is being installed on TFTR to support the D-D run period in 1992. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and secondary tritium containment systems and integrated into TFTR tritium processing systems to provide full tritium pellet capability

Nuclear fuel pellet loading apparatus

International Nuclear Information System (INIS)

Gerkey, K.S.

1979-01-01

An automatic apparatus for loading a predetermined amount of nuclear fuel pellets into a nuclear fuel element to be used in a nuclear reactor is described. The apparatus consists of a vibratory bed capable of supporting corrugated trays containing rows of nuclear fuel pellets and arranged in alignment with the open ends of several nuclear fuel elements. A sweep mechanism is arranged above the trays and serves to sweep the rows of fuel pellets onto the vibratory bed and into the fuel element. A length detecting system, in conjunction with a pellet stopping mechanism, is also provided to assure that a predetermined amount of nuclear fuel pellets are loaded into each fuel element

Numerical analysis of the influence of the fuel pellet shape on the pellet-cladding contact condition

International Nuclear Information System (INIS)

Marajofsky, Adolfo; Denis, Alicia C.; Soba, Alejandro

2004-01-01

One of the problems of greater concern in nuclear fuels operation is that of pellet-cladding interaction (PCI), since it may be cause of fuel failure. In unfailed claddings, the occurrence of contact with the pellet is generally evidenced by a typical deformation pattern known as bamboo effect. In the present work different pellets' shapes are proposed, all of them with a chamfer next to the top and bottom surfaces. The performance of these pellets design is simulated with a numerical code, DIONISIO, previously developed in this working group, which makes use of the finite elements method. It provides the temperature, stress and strain distribution and the inventory of fission gases by analyzing phenomena like thermal expansion, elasticity, plasticity, creep, irradiation growth, PCI, swelling and densification. The pellets' design tested are grouped into two types: those with a straight chamfer running from the central pellet plane to both extremes (R-type pellets) and those with the chamfer occupying one quarter of the pellet's height leaving a central ring of the standard, cylindrical shape (M-type pellets). Different chamfer depths were numerically tested. It was found that the gap increase associated with the introduction of a deep chamfer is responsible for a significant temperature increment. But chamfers which leave a gap of 110 to 150 μm (assuming a normal fuel element with a gap 90 μm thick) gave place to pellets with an adequate thermal response and, moreover, the disappearance of the bamboo effect or even the appearance of an inverse effect, that is, pellets which make contact with the cladding in the region around its middle plane. (author) [es

Pellets for fusion reactor refueling. Annual progress report, January 1, 1976--December 31, 1976

International Nuclear Information System (INIS)

Turnbull, R.J.; Kim, K.

1977-01-01

The purpose of this research is to test the feasibility of refueling fusion reactors using solid pellets composed of fuel elements. A solid hydrogen pellet generator has been constructed and experiments have been done to inject the pellets into the ORMAK Tokamak. A theory has been developed to describe the pellet ablation in the plasma, and an excellent agreement has been found between the theory and the experiment. Techniques for charging the pellets have been developed in order to accelerate and control them. Other works currently under way include the development of techniques for accelerating the pellets for refueling purpose. Evaluation of electrostatic acceleration has also been performed

Impurity pellet injection experiments at TFTR

International Nuclear Information System (INIS)

Marmar, E.S.

1992-01-01

Impurity (Li and C) pellet injection experiments on TFTR have produced a number of new and significant results. (1) We observe reproducible improvements of TFTR supershots after wall-conditioning by Li pellet injection ('lithiumization'). (2) We have made accurate measurements of the pitch angle profiles of the internal magnetic field using two novel techniques. The first measures the internal field pitch from the polarization angles of Li + line emission from the pellet ablation cloud, while the second measures the pitch angle profiles by observing the tilt of the cigar-shaped Li + emission region of the ablation cloud. (3) Extensive measurements of impurity pellet penetration into plasmas with central temperatures ranging from ∼0.3 to ∼7 keV have been made and compared with available theoretical models. Other aspects of pellet cloud physics have been investigated. (4) Using pellets as a well defined perturbation has allowed study of transport phenomena. In the case of small pellet perturbations, the characteristics of the background plasmas are probed, while with large pellets, pellet induced effects are clearly observed. These main results are discussed in more detail in this paper

Economy of wood supply

International Nuclear Information System (INIS)

Imponen, V.

1993-01-01

Research and development of wood fuels production was vigorous in the beginning of the 1980's. Techniques and working methods used in combined harvesting and transportation of energy and merchantable wood were developed in addition to separate energy wood delivery. After a ten year silent period the research on this field was started again. At present the underutilization of forest supplies and the environmental effects of energy production based on fossil fuels caused the rebeginning of the research. One alternative for reduction of the price of wood fuels at the utilization site is the integration of energy and merchantable wood deliveries together. Hence the harvesting and transportation devices can be operated effectively, and the organizational costs are decreased as well. The wood delivery costs consist of the stumpage price, the harvesting and transportation costs, and of general expenses. The stumpage price form the largest cost category (over 50 %) of the industrial merchantable wood delivery, and the harvesting and transportation costs in the case of thinningwood delivery. Forest transportation is the largest part of the delivery costs of logging residues. The general expenses, consisting of the management costs and the interest costs of the capital bound to the storages, form a remarkable cost category in delivery of low-rank wood for energy or conversion purposes. The costs caused by the harvesting of thinningwood, the logging residues, chipping and crushing, the lorry transportation are reviewed in this presentation

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

DEFF Research Database (Denmark)

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

2014-01-01

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

Testing painted wood : past practices at the Forest Products Laboratory and recommendations for future research

Science.gov (United States)

R. Sam Williams

2009-01-01

A brief history of paint research at the Forest Products Laboratory (FPL) in Madison, Wisconsin, sets the stage for a discussion of testing paint on wood and wood products. Tests include laboratory and outdoor tests, and I discuss them in terms of several degradation mechanisms (loss of gloss and fading, mildew growth, extractives bleed, and cracking, flaking, and...

Apparatus for unloading more particularly for nuclear fuel pellets, and to fill tubes with these pellets

International Nuclear Information System (INIS)

Fort, C.; Masson, S.

1985-01-01

The device allows to discharge the nuclear fuel pellets arranged in trays, and to introduce them to form stacks of pellets of determined length in storage tubes of associated diameter. It comprises a carriage to make the pellets slip from each tray on a guide vibrating bowl to a shute and then on a conveyor which loads the pellets into an intermediate tube to form a stack of the said length. A lift moves the intermediate tube transversally to its length between a loading position and a transfer position. Means allow to move a storage tube bundle to put each tube in its turn face to the transfer position. The stack of pellets contained in the intermediate tube which is in the transfer position is thus sent back to the storage tube facing it. The invention applies to pellets which have been sintered in the trays in inert atmosphere. These pellets have to be stored before several examinations and grinding, and finally loading into the cans to constitute fuel rods. These sintered pellets have a cylindrical shape and the invention spares them hard handling which would damage them [fr

Method of manufacturing nuclear fuel pellet

International Nuclear Information System (INIS)

Oguma, Masaomi; Masuda, Hiroshi; Hirai, Mutsumi; Tanabe, Isami; Yuda, Ryoichi.

1989-01-01

In a method of manufacturing nuclear fuel pellets by compression molding an oxide powder of nuclear fuel material followed by sintering, a metal nuclear material is mixed with an oxide powder of the nuclear fuel material. As the metal nuclear fuel material, whisker or wire-like fine wire or granules of metal uranium can be used effectively. As a result, a fuel pellet in which the metal nuclear fuel is disposed in a network-like manner can be obtained. The pellet shows a great effect of preventing thermal stress destruction of pellets upon increase of fuel rod power as compared with conventional pellets. Further, the metal nuclear fuel material acts as an oxygen getter to suppress the increase of O/M ratio of the pellets. Further, it is possible to reduce the swelling of pellet at high burn-up degree. (T.M.)

Leaching of wood ash - Laboratory and field studies; Lakning av vedaska - Laboratorie- och faeltstudier

Energy Technology Data Exchange (ETDEWEB)

Larsson, Per-Erik

2012-02-15

High forest production leads to diminishing amounts of base cations and micro nutrients in forest soils. This is due to uptake in, and harvest of, the trees. Losses can be compensated for by spreading stabilized wood ash on the forest ground, which means recycling of base cations and micro nutrients. Chemical composition of wood ash can easily be described by standard methods in the laboratory. However, this does not include the process of leaching in nature, such as which components and leaching rate for different compounds. During field conditions several factors are added, which are not available in the laboratory. After almost 10 years in the forest soils there still remains large quantities of the original product. Only 10-30 % of the wood ash products and 5 % of the lime product has been leached. In the laboratory study the leached amount was slightly larger, at the most 35 % for wood ash and 20 % for lime. Both studies indicate long time for weathering of the products in forest soils. Slower leaching rate from pellets of wood ash compared to leaching rate from crushed wood ash in the laboratory study is not verified by the field study. This indicates limited possibilities to control rates of leaching in the environment

Research Concerning the Shearing Strength of Black Locust Wood

Directory of Open Access Journals (Sweden)

Mihaela POROJAN

2011-06-01

Full Text Available The paper presents the experimental resultsobtained for the shearing strength of black locustwood (Robinia pseudacacia L. harvested from twogeographical areas (North and South of Romania.Wood is subjected to shearing stress when usedwithin different fields, and especially inconstructions. Tangential stresses are produced inthe shearing sections and they are influenced by thestructure of wood through the position of theshearing plane and of the force direction towards thegrain. Accordingly, several shearing types arepossible. The shearing strengths for the three mainshearing types, both on radial and tangentialdirection were determined within the present study.The evaluation of data was achieved by using theANOVA analysis, in order to test the level ofsignificance depending on the shearing planeorientation and the harvesting area. The obtainedresults were compared to the values mentionedwithin reference literature for this wood species andtwo other hardwood species with similar density. It isworth to be mentioned that the shearing strengths ofblack locust wood from Romania (both from Northand South are generally higher than those indicatedby reference literature for oak and beech. Thisrecommends black locust wood as constructionwood and for other applications where wood issubjected to shearing stress.

Fuel pellet loading apparatus

International Nuclear Information System (INIS)

1980-01-01

Apparatus is described for loading a predetermined amount of nuclear fuel pellets into nuclear fuel elements and particularly for the automatic loading of fuel pellets from within a sealed compartment. (author)

Pneumatic pellet injector for JT-60

International Nuclear Information System (INIS)

Onozuka, Masanori; Hiratsuka, Hajime; Kawasaki, Kouzo.

1990-01-01

The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proven that the device provides high speed pellets as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 2.3km/s at 100 bar propellant gas. (author)

Pneumatic pellet injector for JT-60

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masanori (Mitsubishi Heavy Industries Ltd., Tokyo (Japan)); Hiratsuka, Hajime; Kawasaki, Kouzo

1990-11-01

The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proven that the device provides high speed pellets as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 2.3km/s at 100 bar propellant gas. (author).

High-speed pellet injection with a two-stage pneumatic gun

International Nuclear Information System (INIS)

Reggiori, A.; Carlevaro, R.; Riva, G.; Daminelli, G.B.; Scaramuzzi, F.; Frattolillo, A.; Martinis, L.; Cardoni, P.; Mori, L.

1988-01-01

The injection of pellets of frozen hydrogen isotopes into fusion plasmas is envisioned as a fueling technique for future fusion reactors. Research is underway to obtain high injection speeds for solid H 2 and D 2 pellets. The optimization of a two-stage light gas gun is being pursued by the Milano group; the search for a convenient method of creating pellets with good mechanical properties and a secure attachment to the cold surface on which they are formed is carried out in Frascati. Velocities >2000 m/s have been obtained, but reproducibility is not yet satisfactory

Degradation of copepod fecal pellets

DEFF Research Database (Denmark)

Poulsen, Louise K.; Iversen, Morten

2008-01-01

amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Oresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 +/- 0.49 d(-1)) and minimum (0.52 +/- 0.14 d(-1)) during late winter. Total pellet removal rate ranged...

Uranium dioxide pellets

International Nuclear Information System (INIS)

Zawidzki, T.W.

1979-01-01

Sintered uranium dioxide pellets composed of particles of size > 50 microns suitable for power reactor use are made by incorporating a small amount of sulphur into the uranium dioxide before sintering. The increase in grain size achieved results in an improvement in overall efficiency when such pellets are used in a power reactor. (author)

Sustainability Impact Assessment on the Production and Use of Different Wood and Fossil Fuels Employed for Energy Production in North Karelia, Finland

Directory of Open Access Journals (Sweden)

Matias Pekkanen

2012-11-01

Full Text Available The utilization rate of woody biomass in eastern Finland is high and expected to increase further in the near future as set out in several regional, national and European policies and strategies. The aim of this study was to assess the sustainability impacts of changes in fuel consumption patterns. We investigated fossil and woody biomass-based energy production chains in the region of North Karelia, focusing on some economic, environmental and social indicators. Indicators were selected based on stakeholder preferences and evaluated using the Tool for Sustainability Impact Assessment (ToSIA. The analysis was based on representative values from National Forest Inventory data, scientific publications, national and regional statistics, databases, published policy targets and expert opinion. From the results it became evident that shifting from fossil to wood-based energy production implies some trade-offs. Replacing oil with woody biomass in energy production would increase the local value added remaining in the region, create employment opportunities and would reduce total GHG emissions. However, firewood, wood chips from small-diameter trees from early thinning and wood pellets have high production costs. Moreover, large greenhouse gas emission resulted from wood pellet production. The case study generated valuable reference data for future sustainability assessments and demonstrated the usefulness of ToSIA as a tool presenting existing knowledge on sustainability impacts of alternative energy supply chains to inform decision making.

New pellet production and acceleration technologies for high speed pellet injection system 'HIPEL' in large helical device

International Nuclear Information System (INIS)

Viniar, I.; Sudo, S.

1994-12-01

New technologies of pellet production and acceleration for fueling and diagnostics purposes in large thermonuclear reactors are proposed. The technologies are intended to apply to the multiple-pellet injection system 'HIPEL' for Large Helical Device of NIFS in Japan. The pellet production technology has already been tested in a pipe-gun type pellet injector. It will realize the repeating pellet injection by means of decreasing of the pellet formation time into the pipe-gun barrel. The acceleration technology is based upon a new pump tube operation in two-stage gas gun and also upon a new conception of the allowable pressure acting on a pellet into a barrel. Some preliminary estimations have been made, and principles of a pump tube construction providing for a reliable long term operation in the repeating mode without any troubles from a piston are proposed. (author)

Optimization of bentonite pellet properties

International Nuclear Information System (INIS)

Sanden, Torbjoern; Andersson, Linus; Jonsson, Esther; Fritzell, Anni

2012-01-01

Document available in extended abstract form only. SKB in Sweden is developing and implementing concepts for the final disposal of spent nuclear fuel. A KBS-3V repository consists of a deposition tunnel with copper canisters containing spent fuel placed in vertical deposition holes. The canisters are embedded in highly compacted bentonite. After emplacement of canisters and bentonite blocks, the tunnels will be backfilled and sealed with an in-situ cast plug at the entrance. The main concept for backfilling the deposition tunnels imply pre compacted blocks of bentonite stacked on a bed of bentonite pellet. The remaining slot between blocks and rock will be filled with bentonite pellets. The work described in this abstract is a part of the ASKAR-project which main goal is to make a system design based on the selected concept for backfilling. Immediately after starting the backfill installation, inflowing water from the rock will come in contact with the pellet filling and thereby influence the characteristics of the pellet filling. The pellet filling helps to increase the average density of the backfill, but one of the most important properties beside this is the water storing capacity which will prevent water from reaching the backfill front where it would disturb and influence the quality of the installation. If water flows through the pellet filling out to the backfilling front, there will be erosion of material which also will affect the quality of the installed backfill. In order to optimize the properties regarding water storing capacity and sensitivity for erosion a number of tests have been made with different pellet types. The tests were made in different scales and with equipment specially designed for the purpose. The performed tests can be divided in four parts: 1. Standard tests (determining water content and density of pellet fillings and individual pellets, compressibility of the pellet fillings and strength of the individual pellets); 2. Erosion

Study on the pelletizing of sulfate residue with magnetite concentrate in grate-kiln system

Directory of Open Access Journals (Sweden)

Shufeng Y.

2010-01-01

Full Text Available The experiment on the feasibility of pelletizing with magnetite concentrate and the wasted sulfate residue was carried out, to research the performance of pellet in grate-kiln system and simulate the grate-kiln pelletizing process in the micro-pellet roasting simulation system in laboratory, and the process experiments on preheating and roasting sections were conducted. The results show that in order to obtain pellet with good performance and the magnetite concentrate should be over 20 in mass percent, the suitable pelletizing time is about 10 min and moisture is around 12.5%. Also, according to the process parameters of drying and preheating sections obtained from experiment, it will be successful to use magnetite concentrate and the wasted sulfate residue for pelletizing, which exploits a new way for the use of sulfate residue.

Development of railgun pellet injector using a laser-induced plasma armature. Results of dummy pellet acceleration tests

International Nuclear Information System (INIS)

Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo; Ogino, Mutsuo

1995-01-01

Using the low electric energy railgun system, dummy pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high-speed pellet injection into fusion plasmas. The primary objective of the development is to improve the pellet acceleration efficiency and durability of the rail materials. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. As low electric energy was used, rail materials were used for multiple operations. Tungsten-alloy rail provided longer durability and slightly higher energy conversion coefficient than copper rail. The energy conversion coefficient was from 0.3 to 0.5% using a plastic insulator. A ceramic insulator improved the energy conversion coefficient by 80%. The highest pellet velocity was 1.7 km/s using wooden pellets accelerated by 1m-long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km/s using a 3m-long railgun. (author)

Development of railgun pellet injector using a laser-induced plasma armature. Results of dummy pellet acceleration tests

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo; Ogino, Mutsuo [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Nuclear Energy Systems Engineering Center

1995-03-01

Using the low electric energy railgun system, dummy pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high-speed pellet injection into fusion plasmas. The primary objective of the development is to improve the pellet acceleration efficiency and durability of the rail materials. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. As low electric energy was used, rail materials were used for multiple operations. Tungsten-alloy rail provided longer durability and slightly higher energy conversion coefficient than copper rail. The energy conversion coefficient was from 0.3 to 0.5% using a plastic insulator. A ceramic insulator improved the energy conversion coefficient by 80%. The highest pellet velocity was 1.7 km/s using wooden pellets accelerated by 1m-long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km/s using a 3m-long railgun. (author).

SPINS-IND: Pellet injector for fuelling of magnetically confined fusion systems

Science.gov (United States)

Gangradey, R.; Mishra, J.; Mukherjee, S.; Panchal, P.; Nayak, P.; Agarwal, J.; Saxena, Y. C.

2017-06-01

Using a Gifford-McMahon cycle cryocooler based refrigeration system, a single barrel hydrogen pellet injection (SPINS-IND) system is indigenously developed at Institute for Plasma Research, India. The injector is based on a pipe gun concept, where a pellet formed in situ in the gun barrel is accelerated to high speed using high pressure light propellant gas. The pellet size is decided by considering the Greenwald density limit and its speed is decided by considering a neutral gas shielding model based scaling law. The pellet shape is cylindrical of dimension (1.6 mm ℓ × 1.8 mm φ). For pellet ejection and acceleration, a fast opening valve of short opening duration is installed at the breech of the barrel. A three-stage differential pumping system is used to restrict the flow of the propellant gas into the plasma vacuum vessel. Diagnostic systems such as light gate and fast imaging camera (240 000 frames/s) are employed to measure the pellet speed and size, respectively. A trigger circuit and a programmable logic controller based integrated control system developed on LabVIEW enables to control the pellet injector remotely. Using helium as a propellant gas, the pellet speed is varied in the range 650 m/s-800 m/s. The reliability of pellet formation and ejection is found to be more than 95%. This paper describes the details of SPINS-IND and its test results.

Review of fission-fusion pellet designs and inertial confinement system studies at EIR

Energy Technology Data Exchange (ETDEWEB)

Seifriz, W [Eidgenoessisches Inst. fuer Reaktorforschung, Wuerenlingen (Switzerland)

1978-01-01

The article summarizes the work done so far at the Swiss Federal Institute for Reactor Research (EIR) in the field of the inertial confinement fusion technique. The following subjects are reviewed: a) fission fusion pellet designs using fissionable triggers, b) uranium tampered pellets, c) tampered pellets recycling unwanted actinide wastes from fission reactors in beam-driven micro-explosion reactors, and d) symbiotic fusion/fission reactor studies.

Description of pelletizing facility

Directory of Open Access Journals (Sweden)

Čokorilo Vojin

2006-01-01

Full Text Available A lot of electrical energy in Serbia was used for heating, mainly for domes- tics. As it is the most expensive source for heating the government announced a National Program of Energy Efficiency with only one aim, to reduce the consumption of electric energy for the heating. One of the contributions to mentioned reduction is production of coal pellets from the fine coal and its use for domestic heating but also for heating of schools, hospitals, military barracks, etc. Annual production of fine coal in Serbia is 300,000 tons. The stacks of fine coal make a lot difficulties to the each mine because of environmental pollution, spontaneous combustion, low price, smaller market, etc. To prevent the difficulties and to give the contribution to National Program of Energy Efficiency researchers from the Department of Mining Engineering, University of Belgrade, designed and realized the project of fine coal pelletizing. This paper describes technical aspect of this project.

Solid deuterium centrifuge pellet injector

International Nuclear Information System (INIS)

Foster, C.A.

1982-01-01

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s

Nuclear fuel pellet charging device

International Nuclear Information System (INIS)

Komuro, Kojiro.

1990-01-01

The present invention concerns a nuclear fuel pellet loading device, in which nuclear fuel pellets are successively charged from an open end of a fuel can while rotating the can. That is, a fuel can sealed at one end with an end plug and opened at the other end is rotated around its pipe axis as the center on a rotationally diriving table. During rotation of the fuel can, nuclear fuel pellets are successively charged by means of a feed rod of a feeding device to the inside of the fuel can. The fuel can is rotated while being supported horizontally and the fuel pellets are charged from the open end thereof. Alternatively, the fuel can is rotated while being supported obliquely and the fuel pellets are charged gravitationally into the fuel can. In this way, the damages to the barrier of the fuel can can be reduce. Further, since the fuel pellets can be charged gravitationally by rotating the fuel can while being supported obliquely, the damages to the barrier can be reduced remarkably. (I.S.)

Solid deuterium centrifuge pellet injector

International Nuclear Information System (INIS)

Foster, C.A.

1983-01-01

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength Kevlar/epoxy composite. This arbor has been spin-tested to a tip speed of 1 km/s

Automatic pellet density checking machine using vision technique

International Nuclear Information System (INIS)

Kumar, Suman; Raju, Y.S.; Raj Kumar, J.V.; Sairam, S.; Sheela; Hemantha Rao, G.V.S.

2012-01-01

Uranium di-oxide powder prepared through chemical process is converted to green pellets through the powder metallurgy route of precompaction and final compaction operations. These green pellets are kept in a molybdenum boat, which consists of a molybdenum base and a shroud. The boats are passed through the high temperature sintering furnaces to achieve required density of pellets. At present MIL standard 105 E is followed for measuring density of sintered pellets in the boat. As per AQL 2.5 of MIL standard, five pellets are collected from each boat, which contains approximately 800 nos of pellets. The densities of these collected pellets are measured. If anyone pellet density is less than the required value, the entire boat of pellets are rejected and sent back for dissolution for further processing. An Automatic Pellet Density Checking Machine (APDCM) was developed to salvage the acceptable density pellets from the rejected boat of pellets

Development of repetitive railgun pellet accelerator and steady-state solid hydrogen extruder

International Nuclear Information System (INIS)

Oda, Y.; Azuma, K.; Onozuka, M.; Kasai, S.; Hasegawa, K.

1995-01-01

Development of a railgun pellet accelerator and a steady-state solid hydrogen extruder has been conducted. A railgun accelerator has been investigated for a high-speed repetitive pellet acceleration. The final objective is to develop a railgun system that can achieve a 5km/s speed-class repetitive (2Hz) pellet injection. Improvement in the acceleration efficiency showed a pellet velocity of more than 2km/s using augment rails and a ceramic insulator applied to a 1m-long railgun. The other investigation focused on the development of a steady-state solid hydrogen extruder for continuous pellet injection. Screw-driven extruding system has been chosen to extrude the solid hydrogen filament continuously. Theoretical considerations suggest that temperature control of the system is important in future research. (orig.)

Development of repetitive railgun pellet accelerator and steady-state solid hydrogen extruder

Energy Technology Data Exchange (ETDEWEB)

Oda, Y. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Azuma, K. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Onozuka, M. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Kasai, S. [Japan Atomic Energy Research Inst., Ibaraki (Japan); Hasegawa, K. [Japan Atomic Energy Research Inst., Ibaraki (Japan)

1995-12-31

Development of a railgun pellet accelerator and a steady-state solid hydrogen extruder has been conducted. A railgun accelerator has been investigated for a high-speed repetitive pellet acceleration. The final objective is to develop a railgun system that can achieve a 5km/s speed-class repetitive (2Hz) pellet injection. Improvement in the acceleration efficiency showed a pellet velocity of more than 2km/s using augment rails and a ceramic insulator applied to a 1m-long railgun. The other investigation focused on the development of a steady-state solid hydrogen extruder for continuous pellet injection. Screw-driven extruding system has been chosen to extrude the solid hydrogen filament continuously. Theoretical considerations suggest that temperature control of the system is important in future research. (orig.).

Electrothermal plasma gun as a pellet injector

International Nuclear Information System (INIS)

Kincaid, R.W.; Bourham, M.A.

1994-01-01

The NCSU electrothermal plasma gun SIRENS has been used to accelerate plastic (Lexan polycarbonate) pellets, to determine the feasibility of the use of electrothermal guns as pellet injectors. The use of an electrothermal gun to inject frozen hydrogenic pellets requires a mechanism to provide protective shells (sabots) for shielding the pellet from ablation during acceleration into and through the barrel of the gun. The gun has been modified to accommodate acceleration of the plastic pellets using special acceleration barrels equipped with diagnostics for velocity and position of the pellet, and targets to absorb the pellet's energy on impact. The length of the acceleration path could be varied between 15 and 45 cm. The discharge energy of the electrothermal gun ranged from 2 to 6 kJ. The pellet velocities have been measured via a set of break wires. Pellet masses were varied between 0.5 and 1.0 grams. Preliminary results on 0.5 and 1.0 g pellets show that the exit velocity reaches 0.9 km/s at 6 kJ input energy to the source. Higher velocities of 1.5 and 2.7 km/s have been achieved using 0.5 and 1.0 gm pellets in 30 cm long barrel, without cleaning the barrel between the shots

Decay rate of reindeer pellet-groups

Directory of Open Access Journals (Sweden)

Anna Skarin

2008-06-01

Full Text Available Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (Rangifer tarandus. During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus tidigare. I omr

A synthesis of research on wood products and greenhouse gas impacts

International Nuclear Information System (INIS)

Sathre, R.; O'Connor, J.

2008-11-01

Existing scientific literature on the wood products industry was reviewed in an effort to summarize consensus findings, or range of findings, addressing the net life cycle greenhouse gas footprint of wood construction products. The report sought to clarify whether actively managing forests for wood production was better, worse or neutral for climate change than leaving the forest in its natural state. In addition, it sought to quantify the greenhouse gas emissions avoided per unit of wood substituted for non-wood materials. Forty-eight international studies were examined in terms of fossil energy used in wood manufacturing and compared alternatives, such as the avoidance of industrial process carbon emissions as with cement manufacturing; the storage of carbon in forests and forest products; the use of wood by-products as a biofuel replacement for fossil fuels; and carbon storage and emission due to forest products in landfills. The report presented a list of studies reviewed and individual summaries of study findings. A meta-analysis of displacement factors of wood product use was also presented. It was concluded from all of the studies reviewed, that the production of wood-based materials and products results in less greenhouse gas emission than the production of functionally comparable non-wood materials and products. 48 refs., 1 tab.

Pellet-plasma interactions in tokamaks

DEFF Research Database (Denmark)

Chang, C.T.

1991-01-01

confinement time, offset by the accumulation of impurities at the plasma core is brought into focus. A possible remedy is suggested to diminish the effect of the impurities. Plausible arguments are presented to explain the apparent controversial observations on the propagation of a fast cooling front ahead......The ablation of a refuelling pellet of solid hydrogen isotopes is governed by the plasma state, especially the density and energy distribution of the electrons. On the other hand, the cryogenic pellet gives rise to perturbations of the plasma temperature and density. Based on extensive experimental...... data, the interaction between the pellet and the plasma is reviewed. Among the subjects discussed are the MHD activity, evolution of temperature and density profiles, and the behaviour of impurities following the injection of a pellet (or pellets). The beneficial effect of density peaking on the energy...

ASSESSMENT OF THE USE FOR FERTILISATION PURPOSES INCINERATION ASH PELLETS USING GASIFICATION BURNER LESTER

Directory of Open Access Journals (Sweden)

Marzena Gibczyńska

2016-12-01

Full Text Available The use of biomass in system energetics for the purpose of increasing the share of renewable energy sources in the overall energy mix by biomass and coal co-combustion is not an optimal solution in the light of previous experience in Poland. It is appropriate to develop local biomass market for energy purposes as a basis for future distributed energy generation based on biomass. This solution facilitates the use of ash from biomass combustion for plant fertilisation. The present paper concerns the assessment of the use of ash from combustion of pellets in an innovative gasifying pellet burner – LESTER type, for soil fertilisation. The paper presents the analysis of the content of macro- and microelements in ash against the chemical composition of pellets in relation to permissible contents in fertilisers. The content of phosphorus, potassium, calcium and magnesium in bottom and fly ash from combustion of wood pellet and rye straw in LESTER gasifying burner validates the use of this material for soil fertilisation purposes. However, due to low nitrogen content – comparable to that found in soil, the material is not to be considered as fertiliser supplying this macroelement to soil. The analysed bottom ash used for fertilisation meets the conditions set out in the Regulation of the Minister of Environment of 9 September 2002. However, fly ash should be used with considerable caution due to high content of iron, zinc and nickel. The yield of bottom ash is several times higher than that of fly ash, therefore the possibility of its use in the form of mixtures in adequate proportions should be considered.

Bacteria in decomposing wood and their interactions with wood-decay fungi.

Science.gov (United States)

Johnston, Sarah R; Boddy, Lynne; Weightman, Andrew J

2016-11-01

The fungal community within dead wood has received considerable study, but far less attention has been paid to bacteria in the same habitat. Bacteria have long been known to inhabit decomposing wood, but much remains underexplored about their identity and ecology. Bacteria within the dead wood environment must interact with wood-decay fungi, but again, very little is known about the form this takes; there are indications of both antagonistic and beneficial interactions within this fungal microbiome. Fungi are hypothesised to play an important role in shaping bacterial communities in wood, and conversely, bacteria may affect wood-decay fungi in a variety of ways. This minireview considers what is currently known about bacteria in wood and their interactions with fungi, and proposes possible associations based on examples from other habitats. It aims to identify key knowledge gaps and pressing questions for future research. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Fabrication of Cr-doped UO2 Fuel Pellet using Liquid Phase Sintering

International Nuclear Information System (INIS)

Kim, Dong Joo; Yang, Jae Ho; Kim, Keon Sik; Rhee, Young Woo; Kim, Jong Hun; Oh, Jang Soo; Koo, Yang Hyun

2013-01-01

An enhancement of the thermal conductivity of a pellet can be obtained by the addition of a higher thermal conductive material in the pellet. In addition, the resistance to the PCI can be increased through a plasticity increase of the pellet. Thermal conductivity of ceramic materials is generally lower than that of metallic materials. The thermal conductivity of uranium oxide which is a typical ceramic material is low as well. The steep temperature gradient in the fuel pellet results from the low thermal conductivity. Therefore, the thermal conductivity improvement of a nuclear fuel pellet can enhance the fuel performance in various aspects. The lower centerline temperature of a fuel pellet affects the enhancement of fuel safety as well as fuel pellet integrity during nuclear reactor operation. Besides, the nuclear reactor power can be uprated due to the higher safety margin. So, many researches to enhance the thermal conductivity of nuclear fuel pellet have been performed in various ways. To improve the thermal conductivity of UO 2 pellet, an appropriate arrangement of the high thermal conductive material in UO 2 matrix is one of the various methods. We intended to control a placement of chromium as the high thermal conductive material. The metallic chromium and chromium oxide were arranged in a grain boundary of UO 2 using a liquid phase sintering method. The liquid phase sintering of Cr-doped UO 2 pellet could be adjusted using a control of an oxygen potential in sintering atmosphere

High-rate behaviour of iron ore pellet

Science.gov (United States)

Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

2015-09-01

Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

Ninth wood energy symposium - Reduction of fine-dust emissions and power generation as part of a future power supply system; 9. Holzenergie-Symposium - Feinstaubminderung und Stromerzeugung im Rahmen der zukuenftigen Energieversorgung

Energy Technology Data Exchange (ETDEWEB)

Nussbaumer, T. (ed.)

2006-07-01

This comprehensive report is published by the Swiss Federal Office of Energy (SFOE). A total of fourteen papers were presented at the symposium on the following subjects: Federal Action-Plan in the wood-firing area and emission limits, Fair-Firing - an Action Plan for the prevention of increased emissions and illegal incineration of wastes, fine-dust from wood-fired systems in comparison with diesel soot from the health point of view, practical experience with low-particle, pellets-fired systems, basics and technologies for the precipitation of fine-dust and the influence of particle characteristics and mode of operation as well as two papers on the development of electrical precipitators for wood-fired systems from 200 kW upwards and the practical experience gained with them. Further, papers are presented that deal with small-size electrostatic precipitators, flameless combustion for NO{sub x} reduction and modern pellets technology. The potential and economic viability of wood fuels for the generation of electricity are discussed and a 7 MW{sub e} wood-fired power station is looked at. Finally, the options open for providing a secure supply of energy in Europe are discussed and the role to be played by biomass is examined.

Fuel pellets from biomass: The importance of the pelletizing pressure and its dependency on the processing conditions

DEFF Research Database (Denmark)

Stelte, Wolfgang; Holm, Jens K.; Sanadi, Anand R.

2011-01-01

The aim of the present study was to identify the key factors affecting the pelletizing pressure in biomass pelletization processes. The impact of raw material type, pellet length, temperature, moisture content and particle size on the pressure build up in the press channel of a pellet mill...... act as lubricants, lowering the friction between the biomass and the press channel walls. The effect of moisture content on the pelletizing pressure was dependent on the raw material species. Different particle size fractions, from below 0.5 mm up to 2.8 mm diameter, were tested, and it was shown...

Methods to ensure optimal off-bottom and drill bit distance under pellet impact drilling

Science.gov (United States)

Kovalyov, A. V.; Isaev, Ye D.; Vagapov, A. R.; Urnish, V. V.; Ulyanova, O. S.

2016-09-01

The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rock for various purposes. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The paper presents the survey of methods ensuring an optimal off-bottom and a drill bit distance. The analysis of methods shows that the issue is topical and requires further research.

Recycling process of Mn-Al doped large grain UO2 pellets

International Nuclear Information System (INIS)

Nam, Ik Hui; Yang, Jae Ho; Rhee, Young Woo; Kim, Dong Joo; Kim, Jong Hun; Kim, Keon Sik; Song, Kun Woo

2010-01-01

To reduce the fuel cycle costs and the total mass of spent light water reactor (LWR) fuels, it is necessary to extend the fuel discharged burn-up. Research on fuel pellets focuses on increasing the pellet density and grain size to increase the uranium contents and the high burnup safety margins for LWRs. KAERI are developing the large grain UO 2 pellet for the same purpose. Small amount of additives doping technology are used to increase the grain size and the high temperature deformation of UO 2 pellets. Various promising additive candidates had been developed during the last 3 years and the MnO-Al 2 O 3 doped UO 2 fuel pellet is one of the most promising candidates. In a commercial UO 2 fuel pellet manufacturing process, defective UO 2 pellets or scraps are produced and those should be reused. A common recycling method for defective UO 2 pellets or scraps is that they are oxidized in air at about 450 .deg. C to make U 3 O 8 powder and then added to UO 2 powder. In the oxidation of a UO 2 pellet, the oxygen propagates along the grain boundary. The U 3 O 8 formation on the grain boundary causes a spallation of the grains. So, size and shape of U 3 O 8 powder deeply depend on the initial grain size of UO 2 pellets. In the case of Mn-Al doped large grain pellets, the average grain size is about 45μm and about 5 times larger than a typical un-doped UO 2 pellet which has grain size of about 8∼10μm. That big difference in grain size is expected to cause a big difference in recycled U 3 O 8 powder morphology. Addition of U 3 O 8 to UO 2 leads to a drop in the pellet density, impeding a grain growth and the formation of graph- like pore segregates. Such degradation of the UO 2 pellet properties by adding the recycled U 3 O 8 powder depend on the U 3 O 8 powder properties. So, it is necessary to understand the property and its effect on the pellet of the recycled U 3 O 8 . This paper shows a preliminary result about the recycled U 3 O 8 powder which was obtained by

FBR pellet fabrication - density and dimensional control

International Nuclear Information System (INIS)

Rasmussen, D.E.; Schaus, P.S.

1982-01-01

The fuel pellet fabricating experience described in this paper involved pellet processing tests using mixed oxide (PuO 2 -UO 2 ) powders to produce fast breeder reactor (FBR) fuel pellets. Objectives of the pellet processing tests were to establish processing parameters for sintered-to-size fuel pellets to be used in an irradiation test in the Fast Flux Test Facility and to establish baseline fabrication control information. 26 figures, 7 tables

Uranium dioxide pellets

International Nuclear Information System (INIS)

Zawidzki, T.W.

1982-01-01

A process for the preparation of a sintered, high density, large crystal grain size uranium dioxide pellet is described which involves: (i) reacting a uranyl nitrate of formula UO 2 (NO 3 ) 2 .6H 2 O with a sulphur source, at a temperature of from about 300 deg. C to provide a sulphur-containing uranium trioxide; (ii) reacting the thus-obtained modified uranium trioxide with ammonium nitrate to form an insoluble sulphur-containing ammonium uranate; (iii) neutralizing the thus-formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uranium; (iv) recovering the thus-formed precipitates in a dry state; (v) reducing the dry precipitate to UO 2 , and forming it into 'green' pellets; and (vi) sintering the pellets in a hydrogen atmosphere at an elevated temperature

Biomass - Overview of Swiss Research Programme 2003

International Nuclear Information System (INIS)

Binggeli, D.; Guggisberg, B.

2003-01-01

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

SAF line pellet gaging

International Nuclear Information System (INIS)

Jedlovec, D.R.; Bowen, W.W.; Brown, R.L.

1983-10-01

Automated and remotely controlled pellet inspection operations will be utilized in the Secure Automated Fabrication (SAF) line. A prototypic pellet gage was designed and tested to verify conformance to the functions and requirements for measurement of diameter, surface flaws and weight-per-unit length

A centrifuge CO2 pellet cleaning system

International Nuclear Information System (INIS)

Foster, C.A.; Fisher, P.W.; Nelson, W.D.; Schechter, D.E.

1993-01-01

Centrifuge-based cryogenic pellet accelerator technology, originally developed at Oak Ridge National Laboratory (ORNL) for the purpose of refueling fusion reactors with high-speed pellets of frozen deuterium/tritium,is now being developed as a method of cleaning without the use of conventional solvents. In these applications large quantities of pellets made of frozen CO 2 or argon are accelerated in a high-speed rotor. The accelerated pellet stream is used to clean or etch surfaces. The advantage of this system is that the spent pellets and debris resulting from the cleaning process can be filtered leaving only the debris for disposal. This paper discusses the centrifuge CO 2 pellet cleaning system, the physics model of the pellet impacting the surface, the centrifuge apparatus, and some initial cleaning and etching tests

Nuclear fuel pellet transfer escalator

International Nuclear Information System (INIS)

Huggins, T.B. Sr.; Roberts, E.; Edmunds, M.O.

1991-01-01

This patent describes a nuclear fuel pellet escalator for loading nuclear fuel pellets into a sintering boat. It comprises a generally horizontally-disposed pellet transfer conveyor for moving pellets in single file fashion from a receiving end to a discharge end thereof, the conveyor being mounted about an axis at its receiving end for pivotal movement to generally vertically move its discharge end toward and away from a sintering boat when placed below the discharge end of the conveyor, the conveyor including an elongated arm swingable vertically about the axis and having an elongated channel recessed below an upper side of the arm and extending between the receiving and discharge ends of the conveyor; a pellet dispensing chute mounted to the arm of the conveyor at the discharge end thereof and extending therebelow such that the chute is carried at the discharge end of the conveyor for generally vertical movement therewith toward and away from the sintering boat

Particle Emission Characteristics of Modern and Old-Type Residential Boilers Fired with Wood Logs and Wood Pellets

International Nuclear Information System (INIS)

Johansson, L.S.; Gustavsson, L.; Tullin, C.; Potter, A.; Leckner, B.

2005-01-01

Residential biofuel combustion for heating can be performed in two ways: in a stove heating the surrounding room, or in a boiler heating water to be circulated through a piping system to heat an entire house. In contrast to stoves, wood boilers can be connected to heat storage tanks, which is an advantage from an emission point of view. The present work focuses on comparing emissions from old-type and modern boilers by means of systematic variation of combustion device, fuel quality, firing behaviour, and the influence of heat storage tank. User habits are simulated in a schematic way. The purpose of the comparison is to determine the emission differences between old-type and modern residential biofuel boilers and to quantify emission characteristics of different kind of biofuel combustion

Pellet injector development and experiments at ORNL

International Nuclear Information System (INIS)

Baylor, L.R.; Argo, B.E.; Barber, G.C.; Combs, S.K.; Cole, M.J.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Schechter, D.E.; Sparks, D.O.; Tsai, C.C.; Wilgen, J.B.; Whealton, J.H.

1993-01-01

The development of pellet injectors for plasma fueling of magnetic confinement fusion experiments has been under way at Oak Ridge National Laboratory (ORNL) for the past 15 years. Recently, ORNL provided a tritium-compatible four-shot pneumatic injector for the Tokamak Fusion Test Reactor (TFTR) based on the in situ condensation technique that features three single-stage gas guns and an advanced two-stage light gas gun driver. In another application, ORNL supplied the Tore Supra tokamak with a centrifuge pellet injector in 1989 for pellet fueling experiments that has achieved record numbers of injected pellets into a discharge. Work is progressing on an upgrade to that injector to extend the number of pellets to 400 and improve pellet repeatability. In a new application, the ORNL three barrel repeating pneumatic injector has been returned from JET and is being readied for installation on the DIII-D device for fueling and enhanced plasma performance experiments. In addition to these experimental applications, ORNL is developing advanced injector technologies, including high-velocity pellet injectors, tritium pellet injectors, and long-pulse feed systems. The two-stage light gas gun and electron-beam-driven rocket are the acceleration techniques under investigation for achieving high velocity. A tritium proof-of-principle (TPOP) experiment has demonstrated the feasibility of tritium pellet production and acceleration. A new tritium-compatible, extruder-based, repeating pneumatic injector is being fabricated to replace the pipe gun in the TPOP experiment and will explore issues related to the extrudability of tritium and acceleration of large tritium pellets. The tritium pellet formation experiments and development of long-pulse pellet feed systems are especially relevant to the International Tokamak Engineering Reactor (ITER)

Review of Microalgae Harvesting via Co-Pelletization with Filamentous Fungus

Directory of Open Access Journals (Sweden)

Bo Hu

2013-11-01

Full Text Available Cultivation of microalgae to utilize CO2 and nutrients in the wastewater to generate biofuel products is a promising research objective. However, the process faces tremendous technical difficulties, especially the harvest of microalgae cells, an economically challenging step. Several researchers recently reported co-culturing of filamentous fungi with microalgae so that microalgae cells can be co-pelletized in order to facilitate the cell harvest. This algae pelletization via the filamentous fungi represents an innovative approach to address both the cost and sustainability issues in algae biofuel production and also has potential with direct commercial applications. This paper reviews the current research status in this area and some possible drawbacks of this method in order to provide some possible directions for the future research.

Pellets - the advance of refined bioenergy

International Nuclear Information System (INIS)

Dahlstroem, J.E.

1997-01-01

This conference paper discusses the role of pellets in the use of bioenergy in Sweden. Pellets (P) have many advantages: (1) P are dry and can be stored, (2) P create local jobs, (3) P burn without seriously polluting the environment, (4) P are made from domestic and renewable resources, (5) P have high energy density, (6) P fit well in an energy system adapted to nature, (6) P are an economical alternative, both on a small scale and on a large scale. Pellets are more laborious to use than oil or electricity and require about three times as much storage space as oil. The Swedish pellets manufacturers per 1997 are listed. Locally pellets are most conveniently transported as bulk cargo and delivered to a silo by means of pressurized air. Long-distance transport use train or ship. At present, pellets are most often used in large or medium-sized heat plants, but equipment exists for use from private houses and up to the size of MW. Pellets may become the most important alternative to the fossil fuels which along with electricity today are dominating the small scale market. 1 fig., 1 table

Pellet-plasma interaction studies at ASDEX Upgrade

International Nuclear Information System (INIS)

Kocsis, G.; Belonohy, E.; Gal, K.; Kalvin, S.; Veres, G.; Lang, P.T.

2005-01-01

Pellets produced from cryogenic hydrogen isotopes are used for efficient plasma refueling. Beyond this 'classical' application, pellets pacing the frequency of Edge Localized Modes (ELMs) turned out to be a suitable technique to mitigate the power load on plasma facing components. Although pellet pacing is already integrated in the toolkit for plasma control, its underlying physics is still poorly understood. For investigations aiming to resolve where and how an ELM is triggered by the pellet imposed local perturbation precise knowledge of the ablation profile is required. This renewed and even boosted the interest to understand the interaction of pellets with the hot ambient plasma. Both the investigation of the pellet ablation and also its impact on the target plasma were highlighted. Dedicated investigations require precise information both in the space and time domain. E. g. it is necessary to determine the localization of the pellet at the moment it triggers the ELM as well as the actual imposed 3D distribution of the pellet cloud and its mass deposition profile. By these means, a spatial distribution can be mapped out for a local perturbation of the plasma sufficient to release ELMs. High resolution ablation profile and pellet path measurements at different pellet parameters (mass and velocity) could also help to understand the mechanism of the ELM triggering. Recently pellet-plasma interaction is intensively investigated both experimentally at ASDEX Upgrade tokamak and theoretically based on the obtained experimental data. To gain detailed information an observation system was developed at ASDEX Upgrade consisting of digital cameras that detect the pellet cloud distribution and photo diodes that measure the time evolution of the light emission. The great variety of possible combinations of different images, timings and wavelength selections makes the detection sophisticated. Combination of triggered fast camera images and photo diode signals also enables us

Injection of pellets into the TCA tokamak

International Nuclear Information System (INIS)

Martin, Y.

1993-05-01

This thesis presents experimental results from the analysis of the ablation process of pellets injected into the TCA tokamak. The determination of scaling laws relating the pellet penetration to the pellet and plasma parameters preceding injection, were used to improve the understanding of the interaction of the pellet with the plasma since a) the pellet and plasma conditions preceding injection were varied over a large range, and b) the estimation of the penetration depth takes into account the influence of striations in the deposition profile. Over 400 pellets with a range of sizes and speeds were injected into a range of plasma parameters in order to create a database from which the scaling laws could be deduced. The ablation characteristics were principally measured with two CCD video cameras, which provided good spatial resolution, and two filtered photomultiplier tubes, which provided good temporal resolution of the light emitted from the pellet ablation cloud. In the text, the traditional methods of analysing these diagnostics are examined with special reference to the presumptions that a) the pellet velocity is constant in the plasma, and b) the light intensity determined from the ablation cloud is proportional to the ablation rate. After successive data reduction from the database, in order to separate the effects of varying different parameters, the main observations were that, a) the pellet penetration varies as the square root of the pellet velocity, b) the scaling laws for the other parameters strongly depend on whether the pellet has sufficient velocity to reach the q=1 rational magnetic surface in the tokamak. (author) 45 refs

Volatiles and char combustion rates of demineralised lignite and wood blends

International Nuclear Information System (INIS)

Yilgin, Melek; Pehlivan, Dursun

2009-01-01

Today, much interest is given to the utilisation of materials of plant origin as substitutions of fossil fuels in meeting energy needs to reduce the level of atmospheric pollutant emissions and global warming threat, and emphasis has been placed on the co-combustion of coal and biomass. In this study, volatiles and char combustion behaviour of the fuel pellets composed from demineralised lignite and poplar wood sawdust, were investigated in a cylindrical wire mesh basket placed in a preheated tube furnace. The results have shown that ignition times of the pellets decreased with the burning temperature and shortened further due to demineralisation of lignite. Volatiles combustion rates of the samples did not correlate well with combustion times. However, they can be correlated with their respective proximate volatile matter contents. Char burnout times decreased with increasing combustion rates and correlated well with the respective proximate fixed carbon contents of the samples. Deviations were more considerable in the case of rate data. (author)

Handling of Deuterium Pellets for Plasma Refuelling

DEFF Research Database (Denmark)

Jensen, Peter Bjødstrup; Andersen, Verner

1982-01-01

The use of a guide tube technique to inject pellets in pellet-plasma experiments is described. The effect of the guide tube on the mass and speed of a slowly moving pellet ( nu approximately 150 m s-1) is negligible. To improve the divergence in trajectories of the pellets on leaving the guide tube...

Experimental Observation of Densification Behavior of UO2 Annular Pellet

International Nuclear Information System (INIS)

Kim, Dong-Joo; Rhee, Young-Woo; Kim, Jong-Hun; Yang, Jae-Ho; Kang, Ki-Won; Kim, Keon-Sik

2007-01-01

Recently, in the nuclear industry, one of the major issues is the improvement of a fuel economy. And many efforts have been made to develop a nuclear fuel for a high burnup and extended cycle. In the development of a high performance fuel, in-reactor fuel behavior (fission gas release, pellet-clad interaction, stress corrosion cracking, cladding corrosion, etc.) must be seriously reconsidered. Also, fuel fabrication (high enriched UO 2 powder handling, fuel rod and assembly manufacturing, fabricated fuel rod and assembly storage and transport, etc.) and an enrichment process (5 w/o criticality limit, etc.) must be discussed. A modification and an improvement of the nuclear fuel system will be also required. The typical fuel geometry of a PWR (Pressurized Water Reactor) is composed of a cylindrical pellet with a tubular cladding. And the outer surface of the cladding is cooled with water. However, to allow a substantial increase in the power density, an additional cooling is needed. One of the best ways is the application of the new fuel geometry that is of annular shape and has both internal and external cooling. From this point of view, the double cooled fuel is being developed by KAERI (Korea Atomic Energy Research Institute), and as a part of the project, the development of a fabrication process of a UO 2 annular pellet is now in progress. The dimensional behavior of UO 2 fuel is an important parameter in an irradiation performance. Various investigations (resintering test, model calculation, in-pile dimensional change measuring, etc.) had been performed. In designing a double cooled fuel, the importance of the dimensional behavior of a fuel pellet is higher, because the gap distance between a pellet and cladding can considerably affect on the in reactor fuel performance (gap conductance). And the dimensional behavior of an inner/outer gap is different with a cylindrical pellet, when the pellet shrinks (densification), the inner gap distance decreases and the

Control System for the NSTX Lithium Pellet Injector

International Nuclear Information System (INIS)

Sichta, P.; Dong, J.; Gernhardt, R.; Gettelfinger, G.; Kugel, H.

2003-01-01

The Lithium Pellet Injector (LPI) is being developed for the National Spherical Torus Experiment (NSTX). The LPI will inject ''pellets'' of various composition into the plasma in order to study wall conditioning, edge impurity transport, liquid limiter simulations, and other areas of research. The control system for the NSTX LPI has incorporated widely used advanced technologies, such as LabVIEW and PCI bus I/O boards, to create a low-cost control system which is fully integrated into the NSTX computing environment. This paper will present the hardware and software design of the computer control system for the LPI

Capabilities of nitrogen admixed cryogenic deuterium pellets

Energy Technology Data Exchange (ETDEWEB)

Sharov, Igor; Sergeev, Vladimir [SPU, Saint-Petersburg (Russian Federation); Lang, Peter; Ploeckl, Bernhard; Cavedon, Marco [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kocsis, Gabor; Szepesi, Tamas [Wigner RCP RMI, Budapest (Hungary); Collaboration: ASDEX Upgrade Team

2015-05-01

Operation at high core density with high energy confinement - as foreseen in a future fusion reactor like DEMO - is being investigated at ASDEX Upgrade tokamak. The efficiency of pellet fuelling from the high-field side usually increases with increasing injection speed. Due to the fragile nature of the deuterium ice, however, the increment of pellet mass losses and subsequent pellet fragmentations take place when the speed is increased. Studies show, that admixing of a small amount of nitrogen (N{sub 2}) into D{sub 2} gas can be favorable for the mechanical stability of pellets. This might be helpful for deeper pellet penetration. Besides, seeding by N{sub 2} can enhance plasma performance due to both increasing the energy confinement time and reducing the divertor heat load in the envisaged ELMy H-mode plasma scenario. Fuelling efficiency of N{sub 2}-admixed solid D{sub 2} pellets and their nitrogen seeding capabilities were investigated. It was found that both the overall plasma density increase and the measured averaged pellet penetration depth were smaller in case of the admixed (1% mol. in the gas resulting in about 0.8% in the ice) pellet fuelling. Possibility of the N{sub 2}-seeding by admixed pellets was confirmed by CXRS measurements of N{sup 7+} content in plasma.

The influence of irradiated wood filler on some properties of polypropylene - wood composites

Directory of Open Access Journals (Sweden)

Điporović-Momčilović Milanka

2007-01-01

Full Text Available The problem of compatibility between the wood filler and thermoplastic matrix is of essential importance in composite production. Numerous methods have been developed for increasing this compatibility, which is still representing a challenging objective of composite research throughout the world. The research into these methods is primarily directed towards their efficiency from the viewpoint of the composite performance and their economical acceptability. The latter is of particular importance for the composite production in the developing countries with respect to the shortage of the corresponding funds. With this respect, the utilization of ionizing radiation might have considerable advantages. In this research, the beech wood flour was irradiated by a dose of 10 kGy of 60Co gamma rays for purpose of provoking the changes by the ionizing effect. The effects of ionizing radiation upon the properties of wood particles have been examined by IR spectroscopy and by determination of contents of hydroxyl groups in wood by acetylating as an indirect method. All these methods have been expected to reveal the chemical effects of the applied radiation treatment. The irradiated and the control wood flour were used in order to produce the samples of composite with polypropylene. The polypropylene-wood flour (PP-WF composites were produced with 40% of wood particles having fraction size 0.3 mm. The melt-blended composites were modified with amido-acrylic acid (AMACA as a new coupling agent synthesized for this propose in amount of 6 wt.% (based on wood filler and successively with 0.05 wt.% (based on PP of organic peroxide during mixing step. The composites containing coupling agents showed superior mechanical properties, compared to the untreated one. The highest extent of improvement of tensile was achieved in PP-WFl composites modified with AMACA coupling agent.

Railgun pellet injection system for fusion experimental devices

International Nuclear Information System (INIS)

Onozuka, M.; Hasegawa, K.

1995-01-01

A railgun pellet injection system has been developed for fusion experimental devices. Using a low electric energy railgun system, hydrogen pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high speed pellet injection into fusion plasmas. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. Under the same operational conditions, the energy conversion coefficient for the dummy pellets was around 0.4%, while that for the hydrogen pellets was around 0.12%. The highest hydrogen pellet velocity was 1.4 km s -1 using a 1 m long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km s -1 using a 3 m long railgun. (orig.)

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.

Market opportunities for the utilization of wood waste generated by small sawmills

International Nuclear Information System (INIS)

1992-01-01

Analysis of the amounts and types of wood residue from the British Columbia sawmill and logging industry shows that only ca 50% of the residue is being utilized. On a large scale, increased utilization will mainly be achieved through use for the generation of energy. For small sawmills, a more innovative approach to the problem is needed. To assist in developing the innovative markets and uses for wood residues from the small mills, a series of in-depth interviews was conducted with sawmill operators, resource agencies, and users of wood residue throughout British Columbia. The user markets include other sawmills; pulp, paper, and particleboard plants; energy applications; and agriculture. The results of the interviews are tabulated and analyzed to demonstrate the broad spectrum of wood residue uses currently available as well as those that are emerging. For many small sawmill operations in remote areas, utilization of residues is not economical. As environmental regulations become more stringent, the cost and difficulty of handling or disposing residue will increase, and utilization (even if not economical) will become a valid option compared to disposal. A number of emerging markets for wood residue are noted, many of which are in the agricultural field. Other products which can be made out of wood residues are hog fuel and fuel pellets or briquettes. Small sawmills will not have the residue volumes or funds to establish a briquette plant, but they have expressed interest in supplying residue to any such plant that can be established in their area. 16 refs., 5 figs., 3 tabs

Corrosion of Embedded Metals in Wood: An Overview of Recent Research with Implications for building moisture design

Science.gov (United States)

Samuel L. Zelinka

2013-01-01

ASHRAE Standard 160, Criteria for Moisture-Control Design Analysis in Buildings, specifies moisture design criteria in buildings to prevent moisture damage such as fungal activity and corrosion. While there has been much research on mold and decay fungi in wood buildings, it is often overlooked that wet wood is corrosive to the metal screws...

Railgun pellet injection system for fusion experimental devices

Energy Technology Data Exchange (ETDEWEB)

Onozuka, M. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Oda, Y. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Azuma, K. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Satake, K. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Kasai, S. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun 319-11 (Japan); Hasegawa, K. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun 319-11 (Japan)

1995-11-01

A railgun pellet injection system has been developed for fusion experimental devices. Using a low electric energy railgun system, hydrogen pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high speed pellet injection into fusion plasmas. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. Under the same operational conditions, the energy conversion coefficient for the dummy pellets was around 0.4%, while that for the hydrogen pellets was around 0.12%. The highest hydrogen pellet velocity was 1.4 km s{sup -1} using a 1 m long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km s{sup -1} using a 3 m long railgun. (orig.).

Vertical pellet injection in FTU discharges

International Nuclear Information System (INIS)

Giovannozzi, E.; Annibaldi, S.V.; Buratti, P.

2005-01-01

Central fuelling and pellet enhanced performance modes have been obtained with pellets injected vertically from the high field side on the FTU tokamak. Four phases have been recognized: ablation of the pellets, drifting plasmoids, MHD modes which take the density to the centre of the discharge and finally an anomalous drift which further increases the density peaking. Pellet ablation data have been compared with values from a pellet ablation and deposition code. Comparison between 0.8 and 1.1 MA discharges at a high magnetic field (B T = 7 T) has been carried out: a higher performance has been obtained with the latter due to the higher target density and the larger inversion radius which would increase the effects of m = 1 modes to take the density to the plasma centre

Factors Affecting the Sintering of UO2 Pellets

International Nuclear Information System (INIS)

El-Hakim, E.; Afifi, Y.K.

1999-01-01

Sintering of UO 2 pellets is affected by many parameters such as; UO 2 powder parameters, the conditions followed for preparing the green UO 2 pellets and the sintering scheme(heating and cooling rate, soaking time and temperature). The aim of this work is to study the effect of some these parameters on the characteristics of the sintered UO 2 pellets were qualified according to the technical specifications of Candu fuel. Pressed green pellets at different pressing force (15 to 50 k N) were sintered at 1650 ±20 degree for two hours to study the effect of pressing force on the sintered pellets characteristics; visual inspection, pellet dimensions, density and shrinkage ratio. Compacted green pellets at a pressing force of 48 k N were sintered at different sintering temperature (1600± 20 degree, 1650 ±20 degree, 1700± 20 degree) for two hours to study the effect of sintering temperature on the sintered pellets characteristics. The effect of the heating rate (200,300 and 400 degree per hour) on the sintered pellets characteristics was also investigated. It was found that the pressing force used to compact the green pellets had an effect on the density of the sintered pellets. Pellets pressed at 15 k N have a density of 10.3 g/cm 3 while, those pressed at 50 k N have a density of 10.6 g/cm 3. It was observed that increasing the heating rate to 400 degree /h lead to cracked pellets

Inherent hazards, poor reporting and limited learning in the solid biomass energy sector: A case study of a wheel loader igniting wood dust, leading to fatal explosion at wood pellet manufacturer

International Nuclear Information System (INIS)

Hedlund, Frank Huess; Astad, John; Nichols, Jeffrey

2014-01-01

Large loaders are commonly used when handling solid biomass fuels. A preventable accident took place in 2010, where the malfunction of a front-end wheel loader led to a dust explosion which killed the driver and destroyed the building. The case offers an opportunity to examine the hazards of solid biomass, the accident investigation and any learning that subsequently took place. The paper argues that learning opportunities were missed repeatedly. Significant root causes were not identified; principles of inherent safety in design were ignored; the hazardous area classification was based on flawed reasoning; the ATEX assessment was inadequate as it dealt only with electrical installations, ignoring work operations; and powered industrial trucks had not been recognized as a source of ignition. Perhaps most importantly, guidelines for hazardous area classification for combustible dust are insufficiently developed and give ample room for potentially erroneous subjective individual judgment. It is a contributing factor that combustible dust, although with great hazard potential, is not classified as a dangerous substance. Accidents therefore fall outside the scope of systems designed to disseminate lessons learned and prevent future accidents. More attention to safety is needed for the renewable energy and environmentally friendly biomass pellet industry also to become sustainable from a worker safety perspective. - Highlights: • Wheel loader ignited wood dust, leading to flash fire and explosion. • ATEX assessment inadequate, dealing only with electrical installations. • Guidelines for ATEX zones for combustible dusts are insufficiently developed. • Facility exploded 2002, 2010, root causes not identified, no evidence of learning. • Future repeat explosion likely had facility not been closed down

Wood power in North Carolina

Energy Technology Data Exchange (ETDEWEB)

Cleland, J.G.; Guessous, L. [Research Triangle Institute, Research Triangle Park, NC (United States)

1993-12-31

North Carolina (NC) is one of the most forested states, and supports a major wood products industry. The NC Department of Natural Resources sponsored a study by Research Triangle Institute to examine new, productive uses of the State`s wood resources, especially electric power generation by co-firing with coal. This paper summarizes our research of the main factors influencing wood power generation opportunities, i.e., (1) electricity demand; (2) initiative and experience of developers; (3) available fuel resources; (4) incentives for alternate fuels; and (5) power plant technology and economics. The results cover NC forests, short rotation woody crops, existing wood energy facilities, electrical power requirements, and environmental regulations/incentives. Quantitative assessments are based on the interests of government agencies, utilities, electric cooperatives, developers and independent power producers, forest products industries, and the general public. Several specific, new opportunities for wood-to-electricity in the State are identified and described. Comparisons are made with nationwide resources and wood energy operations. Preferred approaches in NC are co-generation in existing or modified boilers and in dedicated wood power plants in forest industry regions. Co-firing is mainly an option for supplementing unreliable primary fuel supplies to existing boilers.

Power matching for pellet fusion

International Nuclear Information System (INIS)

Martin, R.L.; Arnold, R.C.

1976-01-01

The number of beams required for optimum power transfer from a given power source to the surface of a pellet is derived. The result is valid for linear optical systems, hence, for pellet fusion by laser or high energy ion beams. The optimum number of beams turns out to be inconceivably large for any practical system. Practical pellet fusion by lasers or high energy heavy ion beams must thus compromise physical principles in favor of reduced cost and optical complexity

Production of hydrogen, nitrogen and argon pellets with the Moscow-Juelich pellet target

International Nuclear Information System (INIS)