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1
Malíková, Veronika. "Roštový kotel na spalování dřevní štěpky a tříděného odpadu 50t/h." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417551.
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The diploma thesis deals with the design of a grate boiler for the combustion of a mixture of RDF and wood chips with the specified output and parameters of superheated steam. The introduction consists of stoichiometric calculations and determination of the thermal efficiency of the boiler. The thesis is devoted to determining the dimensions of the boiler, heat transfer calculations, determining pressure losses, checking the heat balance and chlorine corrosion.
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Kozák, Tomáš. "Roštový kotel s přirozenou cirkulací na spalování dřevní štěpky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232155.
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The thesis is dedicated to the design of the steam boiler which burns wood chips, with a natural circulation of the water. It is a grate boiler, which produces 20 t/h of the steam. The output parameters of the steam are 420 °C and 5 MPa. The feedwater temperature is 125 ° C .The thesis gradually deals with stoichiometric calculations and determines the efficiency of the boiler. Then it describes the design of the fireplace and thermal calculations of each heat transfer surfaces. The appendix includes drawings of the boiler.
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Bjurulf, Anders. "Chip geometry : methods to impact the geometry of market chips /." Uppsala : Swedish University of Agricultural Sciences, 2006. http://diss-epsilon.slu.se/archive/00001251/.
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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006.Thesis documentation sheet inserted. Appendix reprints four papers and manuscripts, two co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.
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Bryden, Kenneth Mark. "Computational modeling of wood combustion." Madison, WI, 1998. http://catalog.hathitrust.org/api/volumes/oclc/40048634.html.
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Edelman, John S. "Effects of selected factors on sawmill residue wood chip quality." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-03302010-020129/.
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Wallace, Robert D. "Improving sawmill residue chip quality." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03242009-040800/.
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Weeks, Gregory Andrew. "Analysis of shaker unit parameters to separate whole-tree wood chips." Thesis, Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53197.
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The quality of whole-tree wood chips has been the focus of much attention during the past few years because of the increased use of lower grade wood über in pulp production. The need to up-grade the quality has resulted in the use of some form of screening system to separate acceptable wood chips from unwanted material at most pulp mills.
In order to upgrade the chip quality, a study was conducted to determine the effect of selected parameters of a separation system with an inclined, vibrating screen on screening efficiency. The parameters studied included screen aperture size and frequency of oscillation. Two screen sizes (3/8 and 1/4 inch apertures) and four different frequencies (1.25, 1.50, 1.75, and 2.00 Hertz) were considered. All other shaker unit parameters were held constant. Statistical analysis revealed that the lowest frequency resulted in the highest screening efficiencies for both the pin chips and fines categories. Screening efficiencies were higher with 3/8 inch screen as opposed to 1/4 inch screen, for all frequencies considered, but at 1.25 Hertz, the screening efficiency of fines was only 6 percent better with 3/8 inch screen.
This analysis revealed that the lowest acceleration vectors produced the best screening efficiencies. Velocity and acceleration vectors were directly related to frequency of oscillation since all other parameters were held constant for this study. A Programmer’s Hierarchical Interactive Graphics System (PHIGS) program was developed to graphically simulate the screen motion and to analyze the maximum velocity and acceleration vectors of the upper swing arm (input link). By interactively changing the shaker unit parameters, the screen motion was animated and viewed, with the calculated vectors used in the statistical analysis.Master of Science
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Dyantyi, S. D. (Simphiwe David). "Fungal pretreatment of unextracted and pressurized hot water extracted Eucalyptus Grandis wood chips." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/21655.
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Thesis (MScFor)--University of Stellenbosch, 2007.ENGLISH ABSTRACT: Unextracted (control) and PHWe Eucalyptus grandis wood chips were pulped at 15% active alkali (AA) and 1% antraquinone (AQ). Another batch of wood chips were then inoculated with fungal co-cultures of Aspergillus flavipes and Pycnoporus sanguineus. FCCi wood chips were incubated for four weeks; one PHWe inoculated experimental treatment was incubated for three weeks. The full pulping cycle (160 min) was used to digest the experimental treatments with the exception of one lot of PHWe wood chips that were pulped for 150 minutes. A further experimental treatment of PHWe wood chips was cooked at a reduced AA charge of 14% and 1% AQ. Analysis of variance (ANOVA) of the data from all the experimental treatments was conducted and the differences within the experimental treatments were determined using Statistica (v7, 1984–2006). The F-value (Fischer distribution) and the p-value as well as a non-parametric test known as the Mann-Whitney procedure was tested at the 95% confidence limit. For a further enhancement of the 95% confidence limit the screened yield data was tested by the Bootstrap method. Scanning electron micrographs clearly demonstrated the changed structure and appearance of the chip cross-sectional area after the different pretreatments. Although the mean average results of all the screened pulp yields showed no significant statistical difference (p> 0.05), differences in screened yield of up to 2.5% were obtained. All the weighted means of the rejects showed a significant difference (p < 0.05). Other pulp properties like shive content, chemical consumption, Kappa number, handsheet brightness and strength tests showed mixed results i.e. rejected or accepted the hypothesis (p> or =or < 0.05). The hypothesis that the combined PHWE and FCCI of wood chips would further increase the pulp yield had to be rejected. It is however anticipated that the combination of PHWE with successive co-culture fungal pretreatment would be very beneficial in obtaining higher pulp yields for fully bleached chemical pulp. Further research would be required to test this assumption. This investigation confirmed the expected beneficial effects of combined PHWE and FCCI pretreatments of wood chips on the strength properties. In addition the combined treatment also improved the initial bonding strength potential of the unbeaten fibres.
AFRIKAANSE OPSOMMING: Onbehandelde en met onder druk, warm water uitgeloogde Eucalyptus grandis houtspaanders is respektiefwelik met 15% aktiewe alkali (AA) en 1% antrakinoon (AQ) verpulp. Hierdie is dan met swamkokulture van Aspergillus flavipes en Pycnoporus sanguineus inokuleer en respektiewelik vir drie en vier weke inkubeer. Onder druk uitgeloogde houtspaanders is ook vir 150 minute verpulp by 15% AA 1% AQ en by ‘n verminderde AA van 14%. Pulpevaluasies is uitgevoer op alle eksperimentele behandelinge. Alle onder druk uitgeloogde en met swamkokultuur inokuleerde houtspaanders het ‘n laer pulpopbrengs, uitskot, skilferinhoud, Kappanommer en ‘n hoër RAA en helderheid opgelewer in vergelyking met die vars houtspaanders. Die vars en warm water uitgeloogde houtspaanders het soortgelyke pulpopbrengs opgelewer. ‘n Variansieanalise (ANOVA) van die data van alle eskperimentele behandelings is uitgevoer gebruikmakende van Statistica (V7, 1984 – 2006). Die F-waarde (Fischer-verspreiding) an die p-waarde so wel as ‘n parametriese toets (Mann-Whitney prosedure) is getoets by ‘n 95% betroubaarheidsgrens. Vir ‘n verdere verhoging van die 95% betroubaarheidsgrens van die pulpopbrengs, is die beskikbare data weer getoets met die Bootstrap-metode. Alle gemiddelde pulpopbrengswaardes het geen beduidende statistiese verkil opgelewer nie (p>0.05), alhoewel verskille van tot 2.5% in pulpopbrengs verkry is. Alle gemiddelde uitskotwaardes het ‘n beduidende verskil getoon (p<0.05). Die ander pulpeienskappe soos skilferinhoud, verbruik aan chemikalieë, Kappagetal, handvel helderheid en sterktewaardes het gemengde resultate opgelewer maw verwerping of aanvaarding van die hipotese p> or =or < 0.05. Die hipotese dat die gekombineerde PHWE en FCCI van die houtspaanders die pulpopbrengs verder sou verhoog moes verwerp word. Daar word egter verwag dat die kombinasie van PHWE met opeenvolgende swamkokultuur behandeling baie voordelig sou wees op die pulpopbrengs van ‘n ten volle gebleikte chemiese pulp. Verdere navorsing is nodig om hierdie veronderstelling te toets. Die ondersoek het die verwagte woordelige effek van die gekombineerde PHWE en FCCI voorbehandelings van die houtspaanders op die papierstrkte-eienskappe bevestig. Bo en behalve dit, het die gekombineerde behandeling ook die aavanklikte bindsterkte potensiaal van die ongeklopte vessels verbeter.
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Laytner, Frank. "Fundamentals and technology of wafer drying." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/30728.
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The commercial rotary dryers used to dry wood wafers (of approximate dimensions 0.63 mm thick, 50 mm wide and 76+ mm long) for the production of panelboard are modified versions of agricultural dryers and have not been designed for the optimal drying of wood wafers. The lack of available information on wafer drying necessitated that the first goal of this research was the characterization of wafer drying behaviour. After the important parameters of wafer drying were identified, the applicability of fluidized bed technology to wafer drying was assessed and an industrial size dryer was designed. The proposed fluidized bed wafer dryer was then compared to a commercial rotary dryer in terms of energy efficiency.
Wafer drying behaviour was investigated in two factorial experiments. Three lengths of wafers (25 mm, 44 mm and 63 mm) were individually dried in a 0.15 m draft tube at temperatures of 90°C, 120°C and 150°C. The statistical analysis of the resultant drying rate curves showed that the drying behaviour of aspen wafers was influenced by the effect of wafer length on the external heat and mass transfer rates to the wafer surface, and on the length of internal pathways for bulk flow and diffusion of water. The external drying conditions had a decreasing effect on drying rate until about 10% moisture content at which time drying became limited by internal heat and mass transport.
The initial assessment of fluidized bed technology for wafer drying used a 0.15 m semi-cylindrical column for the determination of wafer drying rate curves and wafer behaviour in a fluidized bed of inert particulate solids at excess superficial velocities of 0.25 to 1.0 m/s. Wafer drying times in a bed of 0.5 mm sand at 150°C were about 40% of the drying times for wafers dried by forced convection of air at the same temperature and twice the superficial velocity (~ 1 m/s).
Wafer movement in the fluidized bed followed the circulation patterns of the emulsion phase and was thus dependent on the bubbling behaviour of the bed. A minimum excess superficial velocity of 0.25 m/s (depending on distributor design) was required to prevent permanent settling of the wafers to the distributor.
Preliminary experimentation on a 2-compartment bed showed that wafers could be circulated through the two compartments in near plug flow. However, the application of this technique to a 4-compartment continuous fluidized bed wafer dryer was unsuccessful
because of the separation of sand and wafers caused by slugging beds in two of the compartments.
A preliminary design was prepared for an industrial size, 5-compartment fluidized bed wafer dryer to approximate plug flow of wafers by a series of well-mixed fluidized beds in series. The design calculations showed that this dryer was more efficient in terms of energy and plant space than a conventional triple pass rotary dryer.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Girgis, Elisabeth. "Fuel devolatilization in packed bed wood combustion." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26645.
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Packed bed combustion is the burning of solid fuel particles supported by a grate with the combustion air supplied from below. The combustion process is divided into four main stages: drying, devolatilization, volatiles combustion and char combustion. Biomasses proposed as renewal energy sources, such as wood, have a very high volatile content (∼80%). Therefore mechanistic models developed for the prediction of bed characteristics during biomass combustion must include devolatilization and volatile combustion stages in order to correctly predict combustion behaviour for better emissions control and process efficiency. A novel in-situ sampling method for tar, a major pyrolysis product, was developed that allows its concentration to be measured at various heights within the packed bed and appears to work satisfactorily. A series of experiments on packed bed combustion were conducted in a laboratory 'pot' type combustor. Two different equivalent particle size diameters (2.8 cm and 3.2 cm) of untreated spruce wood and two different airflow rates (0.025 kg/m2s and 0.03 kg/m 2s) were tested at a 22 cm bed height. Although the experimental data show scatter, the measurements indicated that pyrolysis occurred primarily within two particle diameters of the top of the bed, with large amounts of tar and CO and somewhat less CO2 being produced. This research also expanded a numerical model for packed bed combustion of solid fuels with the addition of a simple first order pyrolysis reaction, in which fixed proportions of the products were set as light volatiles of CO and CO2 with the balance as tar. The model results compared well with bed temperature, particle size and density measurement throughout the bed and gas concentration (CO, CO2, O2, and CH4) measurements in the reduction and oxidation zone.
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Sharp, J. C. "The in-woods cleaning of whole-tree-chips." Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/74534.
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This research examined Whole-Tree-Chip cleaning methods applicable to field operations in Pinus taeda L. (Loblolly pine) on the coastal plain of South Carolina. Objectives were: 1) to examine current and potential cleaning methods, and 2) develop and test two cleaning approaches suggested by past research.
An open top chip van was modified to: a) determine the dispersion and composition of whole-tree-chip fractions by the installation of sampling buckets and floor pans and b) provide a platform for testing two cleaning systems. System one consisted of anti-clogging screens which pre-screened chips as they were discharged at the mill. It also allowed floor pans to sample the load for fines. System two utilized a radial blade blower which altered chip stream composition during loading by the Whole-Tree-Chipper.
Eight trials were conducted over a six month period using a Morbark 22 chipper. Results indicated floor screens could have been more effectively positioned at the chip dump. As installed, and pin they successfully removed 1% of the load in fines chips. The best chip stream treatment involved double deflection: first from a vacuum assisted primary screen located in the van roof, and then from a passive screen located below and behind the first. This design reduced bark and fines by one-third.Master of Science
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Salami, Najdat. "Gasification of Pine Wood Chips with Air-Steam in Fluidized Bed." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234253.
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Tato práce studovala vliv použití vzduchu a páry jako zplynovacího činidla ve zkapalňovacím generátoru plynu na vlastnosti vyprodukovaného plynu (oxid uhelnatý, vodík, obsah dehtu a nízká výhřevnost). Tato studie byla založena na experimentech které byly provedeny ve fluidním generátoru plynu Biofluid 100 v laboratoři Energetického ústavu technologické univerzity Brno s použitím páry jako zplynovacího činidla a borovicového dřeva jako výchozí suroviny. Cílem této dizertační práce je stanovit nejlepší provozní parametry systému při užití vodní páry a vzduchu ve zplynovacím zařízení biofluid 100, při kterých se dosáhne nejvyšší kvality plynu. K dosažení tohoto cíle bylo provedeno mnoho experimentů studujících účinky teploty reaktoru(T101), poměru páry a biomasy (S/B) poměru páry a vzduchu (S/A), teploty dodávané páry (Tf1), ekvivalentního poměru ER,ve složení vyprodukovaném plynu, výhřevnost, výtěžnost plynu, efektivnost přeměny uhlíku a účinnost zplynovače. Výsledky experimentů ukázaly, že zvýšení teploty reaktoru vede ke zvýšení obsahu vodíku a oxidu uhelnatého, výhřevnosti, výtěžnosti plynu, efektivnosti přeměny uhlíku, efektivnosti zplynovače a ke snížení obsahu dehtu. Příliš vysoká teplota reaktoru ale snižuje výhřevnost plynu. Dodáváním páry se zvýšila kvalita plynu, vyšší H_2,LHV a nižší obsah dehtu. Přesto ale nadměrné množství páry snižuje zplyňovací teplotu a tím i kvalitu plynu. Poměr páry a biomasy při kterém se dosáhne nejlepší kvality plynu se zvýší s teplotou reaktoru. Bylo zjištěno, že kdykoli byla teplota páry (Tf1) vyšší, byl plyn více kvalitní, ale zvyšování teploty páry také zvyšuje ekonomické náklady na vyprodukovaný plyn což se při masové produkci plynu musí brát v úvahu. Efekt ekvivalentního poměru ER, byl studován postupným zvyšováním, bylo zjištěno, že nejlepší ekvivalentní poměr pro dosažení nejvyšší kvality plynu byl kolem 0.29, při ER > 0.29 byl obsah hořlavého plynu snížen a to vedlo ke snížení kvality plynu. Obsah dehtu se snižuje jak zvýšením teploty reaktoru tak poměrem páry k biomase. Podle výsledků experimentů a diskuze, bylo zjištěno, že při použití směsi páry a vzduchu se kvalita plynu zvýší, parametry pro dosažení nejvyšší kvality vyprodukovaného plynu při experimentálních podmínkách jsou: T101 =829 S/B=0.67((kg steam)/(kg biomass)) ,S/A=0.67((kg steam)/(kg air)) , ER= 0.29 and a Tf1 je nejvyšší možná teplota,při které se vodík zvýší z 10.48 na 19,68% a výhřevnost z 3.99 na 5.52(MJ/m^3 ) a obsah dehtu z 1964(mg/m^3 ) na 1046(mg/m^3 ) zvýšením z 0 na 0.67 při T101=829 .
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Chow, Bosco. "Heat transfer and pressure drop in fixed beds of wood chips." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25085.
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Heat transfer from a flowing gas to a fixed bed of dried Dougas-fir wood chips has been studied by a transient method. Hot air at about 130°C flowed upward through 0.2 m dia x 1 m deep beds of commercially prepared wood chips which had been screened for thickness. Four different wood chip sizes were used, which varied in mean thickness from 2.44 to 7.26 mm. The thickest chips were 18.4 mm wide x 36.3 mm long. Gas temperatures were measured at a number of axial positions as the bed temperature rose from its initial temperature of about 20°C. Heat transfer coefficients were calculated by fitting the air temperature profiles to a transient mathemical model for plug flow of gas through a bed of slab-shaped particles with finite internal thermal resistance. The heat transfer model was solved analytically using an approach pioneered by Amundson (10) for fixed beds of spherical particles and based on Rosen's (6,7) function. This solution has not appeared elsewhere in the literature, and is shown to converge to that of Anzelius (1) if the Biot number for the particle approaches zero. Experiments were done at a series of air velocities with four wood-chip thicknesses and with spherical catalyst particles to provide a check on the technique. The effect on heating rate of 30% by volume steam in the incoming air was investigated. For selected experiments, solid temperatures within the wood chips were measured. A correlation of the heat transfer coefficients is presented. Pressure drop was measured as a function of air velocity for different sizes of wood chips at room temperature and the results are compared with predictions of the Ergun equation.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Agarwal, Niraj. "Modeling of continuous pulping /." Thesis, Connect to this title online; UW restricted, 1993. http://hdl.handle.net/1773/5564.
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Eriksson, L. Gunnar. "Combustion of solid waste from wood-based ethanol production /." Luleå, 2005. http://epubl.luth.se/1402-1757/2005/22.
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Krecl, Patricia. "Impact of residential wood combustion on urban air quality." Doctoral thesis, Stockholm : Department of Applied Environmental Science (ITM), Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7682.
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Vu, Binh Ngan. "Mutagenicity assessment of aerosols in emissions from wood combustion." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/5802.
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Mestrado em Estudos AmbientaisPolycyclic aromatic hydrocarbon (PAH) extracts of PM2.5 collected from combustion of seven wood species and briquettes were tested for mutagenic activities using Ames test with Salmonella typhimurium TA98 and TA100. The woods werePinuspinaster (maritime pine), Eucalyptus globulus (eucalypt), Quercussuber (cork oak), Acacia longifolia (golden wattle), Quercusfaginea (Portuguese oak), Oleaeuropea (olive), and Quercus ilex rotundifolia (Holm oak). Burning experiments were done using woodstove and fireplace, hot start and cold start. A mutagenic/weak mutagenic response was recorded for all species except golden wattle. The extracts with indirect acting mutagenicity were mainly obtained from fireplace and cold start conditions. The strong mutagenic extracts were not correlated with high emission factors of carcinogenic PAHs. Several samples were weak mutagens at low concentration of PAHs. The negative result recorded for the golden wattle extracts is positive since after confirmation, this species can be recommended for domestic use.
(FCT) - PTDC/AMB/65706/2006 (BIOEMI)
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Fan, Xiaolin. "Material flow in a wood-chip refiner." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63977.
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Lundgren, Joakim. "Performance of a new wood-chips fired boiler for small district heating systems." Licentiate thesis, Luleå, 2002. http://epubl.luth.se/1402-1757/2002/31.
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Edgerton, Sylvia Anne. "Gaseous tracers in receptor modeling : methyl chloride emission from wood combustion /." Full text open access at:, 1985. http://content.ohsu.edu/u?/etd,84.
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Guo, Wendi. "Self-heating and spontaneous combustion of wood pellets during storage." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/43931.
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Self-heating of wood pellets is a major concern during long term storage. Internal temperatures rose to 57℃ in 10 days in a wood pellet silo of 21.9 m diameter in Fibreco Inc. (Vancouver, Canada) after pellets (about 20℃) were loaded into the silo. Self-heating could lead to serious accidental fires, causing enormous damage and danger to workers. In this study, the self-heating rate at different temperatures was experimentally determined, and the thermal properties were measured. for wood pellets produced in British Columbia, Canada. The factors such as moisture content, pellet age and environment temperature were investigated and their impacts on the self-heating process were analyzed.
Moisture content has a significant effect on effective thermal conductivity and specific heat capacity of packed pellets, but has no effect on the self-heating at the temperature range of 30℃ to 50℃. Pellets age and environment temperature are two major factors impacting the self-heating and off-gassing process. The self-heating rate is significantly increased at higher a temperature and eventually will lead to a thermal runaway when the ambient temperature is high enough. Experimental results show that the critical ambient temperature for thermal runaway decreases as the reactor size increases. The reaction kinetics was studied at both low temperatures (30℃ to 50℃) and high temperatures (100℃ to 200℃) and kinetic parameters were extracted from experimental results and correlations were developed.
Based on all measured properties data and kinetics data, a two-dimensional axi-symmetric self-heating model was developed to predict the self-heating process and thermal runaway in large wood pellet silo. The influences of cooling airflow rate, wall insulation, and dimension of the storage container, ambient temperature and wind condition were studied. The results show that air ventilation inside of the silo is a very effective approach for reducing self-heating and preventing thermal runaway at ambient temperatures lower than 330 K. The critical ambient temperature for a 21 m diameter silo can be as low as 36℃ in the absence of air ventilation. The current model can be used to safe guide the design and operation of large industrial wood pellets silos.
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Ortega, Mario. "Improved combustion in wood stoves : Reduksjon av utslipp i vedovner." Thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9802.
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There are two main ways of measuring particle emission from wood combustion. Firstly, particles can be sampled directly in the chimney. Secondly, a dilution tunnel can be used, thus cooling the flue gases parallel to diluting. The purpose of this work is to investigate the differences between both measurements and establish which is the best method to measure particle emission from wood combustion. The approach is to perform particle emission measurements in the chimney and in a dilution tunnel simultaneously during the combustion of wood in a small-scale appliance. Moreover, Flame Ionization Analysis will be carried out to understand the contribution of condensed organic compounds to the total particulate matter emission. The particle emission measured in the dilution tunnel was between 5 and 12 times higher than in the chimney. The more unfavourable combustion conditions, the larger the difference between both measurements was seen. The results also show a factor of about 2,5 between both particle emission measured in the stack and Total Hydrocarbon content in the flue gas and particle emission measured in the dilution tunnel, indicating that about 35 % of the hydrocarbons measured in the stack with the Flame Ionization Detector condense along the dilution tunnel accounting for approximately 85 % of the total particle emission found at this location.
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Palacios, Sara. "Decolourization of azo and anthraquinone dyes by mean of microorganisms growing on wood chips." Thesis, Växjö University, School of Technology and Design, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-5168.
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Reactive Black 5 and Procion Red MX 5B, an azo and anthraquinone dye repectively were decoulorized by mean of microorganisms growing on wood chips. The process consisted of three reactors, two anaerobic reactors and one aerobic reactor. The anaerobic process was used in order to make it possible to break the nitrogen bond of the azo group, (-N=N-) and the aerobic one to increase the possibility for the degradation of possible intermediates. After pumping wastewater through the system it was shown that mixtures or Reactive Black 5 and Procion Red MX 5B were efficiently decolourised at 50 mg/l as well as 200 mg/l of each of the dyes.
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Mårtensson, Tomas. "Application of enzymes for pre-treatment of wood chips for energy efficient thermomechanical pulping." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-77463.
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Thermomechanical pulping (TMP) is a highly energy intensive process where most of the energy is used in therefining of chips to fibres. Various ways of reducing the energy consumption have earlier been studied, for examplechange of refiner pattern, addition of various chemicals, and also some biochemical implementation in the form of fungus and enzymes. This study includes pre-trials with the enzymes pectin lyase and pectin esterase,multipectinase, xylanase, and mannanase. The results are studied via a reducing sugar assay, an enzymatic assayusing spectrophotometry, and capillary zone electrophoresis. The study also includes results from a pilot scalerefining with multipectinase, xylanase, and mannanase, performed with a wing refiner at Helsinki University.Reductions of energy consumption in TMP by pre-treatment of Norwegian spruce chips are investigated and apotential reduction of energy consumption of 6 % is indicated.
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Lenz, Hannes [Verfasser]. "Dry matter losses during storage of wood chips from short rotation coppice / Hannes Lenz." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1125942819/34.
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Wretborn, Tobias. "Pyrolysis of Wood Chips : Influence of Pyrolysis Conditions on Charcoal Yield and Charcoal Reactivity." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-179.
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At a steel mill, charcoal from biomass is a potential substitute to coal as a reducing agent in the Blast Furnace. The steel industry accounts for 5 % of the global CO2 emissions. Charcoal, being a renewable fuel, has the potential to mitigate the steel industry’s contribution to global warming. If charcoal were to replace the pulverized coal injected into one of Sweden´s two blast furnaces an estimated 1,13 Mton raw biomass per year would be required, this is equivalent to 2,5 % of the total available biomass in Sweden the year 2020 . If this is to be realized, a well optimized pyrolysis process for charcoal production would be required, a process with high charcoal yield that minimize the biomass consumption. This report presents a study on pyrolysis of wood chips. The two main objectives of this work have been to find pyrolysis conditions, applicable in a real process, that increase the charcoal yield and also to investigate how the reactivity of the charcoal is affected by these conditions. A hypothesis with two approaches has been proposed and evaluated experimentally. It has been proposed that the charcoal yield is increased if the tar found in the pyrolysis gases are condensed and returned to impregnate the ingoing wood before undergoing a second pyrolysis step. Or, the charcoal yield is increased by letting the tar impregnate the outgoing charcoal before the two undergoes a second pyrolysis step. The hypothesis has been evaluated in a laboratory where pyrolysis has been conducted on chips from fir wood together with bio-oil. The bio-oil has been used to resemble tar. It has been concluded that by recycling tar the charcoal yield is increased. Pyrolysis of fir wood at 340 oC yields 32 % charcoal. If the wood is impregnated before the pyrolysis with an amount of bio-oil equivalent to a tar yield of 25 % the charcoal yield is increased to 37,7 %. It is possible to say, with 80 % confidence, that pyrolysis of wood and bio-oil gives a higher charcoal yield if the two undergoes pyrolysis while being in contact with each other instead of being separated. The charcoal yield is not increased by pyrolysis of charcoal impregnated with bio-oil. There is no difference in reactivity between charcoals from impregnated wood and plain wood.
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Broberg, Henrik. "Steaming of Wood Chips - Experimental determination of heating times and effect of different parameters." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259926.
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The presteaming of wood chips is an important step in the chemical pulping industry. It removes the air from within wood chips, allowing the cooking liquor to better impregnate wood chips, which leads to a more uniform cooking process, and lowers the amount of rejects. When steaming at atmospheric pressure, it is important that the temperature of the wood chips reach 100ᴼ C, as otherwise there will be an equilibrium leaving some air left inside. Having poorly steamed chips in a process could cause severe problems when it comes to reaching the targeted kappa number, or having the adequate retention time in the digester. There are a few different ways in which the wood chips are presteamed within the industry, however, there is little experimental data regarding the heating time of wood chips that can be used when designing these systems. Most studies have mainly focused on the air removal, or improvement of the impregnation step, and the few studies that have included the heating of the wood chips were limited to only one type of wood chip, or failed to specify the experimental details. Therefore, handmade wood chips pine and birch, two tree species commonly found in Sweden, were steamed in an ATEX designed digester with a steam jacket. The wood chips had thermocouples inside them and the temperature and time was recorded, and the effect of different parameters on the heating could thus be studied.The results revealed that there could be more than a minute in average time difference between wood chips of different thicknesses, both for birch and pine, although the difference in heating time was more linearly correlated to thickness for the birch chips. Pine chips of different thickness were also studied when the pressure inside the digester was allowed to build up, which showed that it is mainly thicker chips that have reduced heating time under such circumstances, as the thinner chips stop heating for a while when the steam condensates on colder surroundings. When comparing heartwood and sapwood chips, it was noted that the difference in heating time could be around 1 minute at most for pine, but only a few seconds for birch. This was most likely due to the pine heartwood and sapwood having distinct moisture contents, 25 % and 58 % respectively, while it was 41% and 42 % in birch heartwood and sapwood. Birch and pine chips wee also steamed together, however, the difference in heating time was only a few seconds on average. When comparing these experimental results with simulation data of the steaming of wood chips, it fit rather well when it came to the general heating time. However, the effect of increased moisture content had a much larger impact in the simulations, which predicted that more moist wood chips would need several minutes more steaming time, while the experiments only showed at difference of, at most, around 1 minute. When comparing with old experimental data, that has been the basis for the design of older steaming processes, it gave very distinct results, where the effect of thickness did not have as big of an impact as in the old data. No further comparison could be made, however, as the experimental conditions for the old experimental data were not known. Based on these results, it was noted that a steaming time of at least 5 minutes would be needed to ensure that even the largest and more moist chips could reach 100ᴼ C in this system. Finally, the condensate from the handmade birch and pine chips was analyzed. It revealed the presence of low molecular weight compounds like methanol, formic acid and acetic acid. Common metal ions were also present,although the amount of sodium ions clearly surpassed the rest. The pH of the pine condensate was measured and it was very high, which implies that the condensate was contaminated.Basning av flis är ett viktigt steg inom kemisk massaindustri. Det avlägsnar luft från flisens insida vilket gör att impregneringen av luten blir bättre, vilket i sin tur leder till en jämnare kokning och färre rejekt. När basningen sker vid atmosfärstryck är det viktigt att flisen når en temperatur på 100ᴼ C, annars kommer det finna ett jämviktstillstånd där lite luft blir kvar på insidan. Att ha otillräckligt basad flis i en process skulle kunna orsaka stora problem när det gäller att nå önskade kappatal, eller att ha en önskad retentionstid i kokaren.Basningen görs på ett par olika sätt inom industrin, men det finns väldigt lite experimentell data tillgänglig angående flisens upvärmning, som skulle kunna användas när dessa system designas. De flesta vetenskapliga studier har fokuserat på luftborttagningen eller på förbättringar av impregneringssteget, medan de få studier som inkluderat mätningar av temperaturen ofta varit begränsade till ett slags trä, eller så har de inte inkluderat detaljer kring experimentet. Därför basades handgjorda flisbitar av björk och tall från Sverige i en ATEX-designad kokare med en ångjacka. Flisen hade termoelement inuti och temperaturen samt tiden kunde avläsas, vilket gjorde det möjligt att studera effekten av olika parametrar. Resultaten visade att det kunde skilja mer än en minut i uppvärmningstid mellan flisbitar av olika tjocklekar, både för tall och björk, även fast skillnaden i uppvärmningstid var mer linjärt relaterad till tjockleken för björkflisen. Tallflisen studerades också när trycket inuti kokar tilläts stiga vilket visade att det de tjockare flisbitarnas uppvärmningstid som kortas ned mest, eftersom de tunnare flisbitarna slutar värmas upp när ångan börjar kondensera på kallare ytor runt omkring. När flis av splintved och kärnved jämfördes visade det sig att skillnaden i uppvärmningstid kunde vara omkring 1 minut för tall, men endast ett par sekunder för björk. Detta beror troligtvis på att kärnveden och splintveden i tall hade stora skillnader i fukthalt, 25 % respektive 58 %, medan det för björk var 41 % och 42%. Björkflis och tallflis basades även tillsammans men det skillde bara ett fåtal sekunder i genomsnitt i uppvärmningstid. När den experimentella datan jämfördes med data från simuleringar visade det sig att de stämmer väl överens när det gäller uppvärmningstiden i allmänhet. Å andra sidan förutspådde simuleringsdatan att en ökad fukthalt skulle leda till flera minuters skillnad i uppvärmningstid, medan endast 1 minuts skillnad uppmättes. När jämförelser gjordes med gammal experimentell data som använts som grund för tidigare processers design, var resultaten ganska olika eftersom den gamla datan visade en större effekt av ökad tjocklek än den som uppmättes.Tyvärr kunde inte fler jämförelser göras eftersom detaljerna kring experimentet bakom den gamla datan inte var kända. Slutligen analyserades även kondensatet från de handgjorda flisbitarna av tall och björk. Det visade att det fanns små mängder av små polära organiska ämnen, såsom metanol, myrsyra och ättiksyra. Vanliga metalljoner detekterades också, där mängden natrium var klart större än övriga metalljoner. Tallkondensatets pH mättes och det visade sig vara väldigt högt, något som tyder på att det troligtvis var förorenat.
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Gauggel-Lewandowski, Susanne [Verfasser]. "Toxicological Characterization of Particulate Matter from Wood Combustion / Susanne Gauggel-Lewandowski." Konstanz : Bibliothek der Universität Konstanz, 2013. http://d-nb.info/1080962328/34.
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Kirk, Randall P. "The impact of residential wood combustion on indoor particulate matter levels." Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/539632.
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This study concentrates on indoor air pollution, specifically particulate matter, as a result of woodburning in the home. Three single-family residences in Richmond, Indiana, equipped with identical airtight woodburning stoves and using a controlled wood supply, were monitored for a 49-day period in 1987. Particluate matter samples were collected during periods of active wood combustion and periods absent of wood combustion using low-volume samplers. Significant differences were found in two of the three houses when wood combustion and non-wood combustion periods were compared. No relationship was found between particle levels and time of day, ambient air temperature, pounds of wood burned, refueling duration or refueling frequency. It was concluded that woodburning can affect the quality of indoor air in particulate matter levels.Department of Natural Resources
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Bari, Aynul. "Investigation of particulate matter originating from wood combustion in residential areas." Aachen Shaker, 2009. http://d-nb.info/996003797/04.
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Nunes, Inês Filipa Santos. "Evolution of phenolic and sensorial characteristics of rosé wines aged with different alternative wood chips." Master's thesis, ISA, 2017. http://hdl.handle.net/10400.5/14840.
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Mestrado em Viticultura e Enologia / Instituto Superior de AgronomiaThe aim of this study was evaluating the effects of cherry (Prunus avium) and oak (Quercus petraea) chips in the phenolic, volatile and sensorial profile of a Portuguese rosé wine, made from Touriga attempting to understand whether the application of cooperage, including alternative woods, is potentially enhancing. For this purpose, several chemical analyses were carried out; for musts (at 0, 2, 6, 8,10 and 20 fermentation days), total phenols, non-flavonoids, chromatic characteristics, and colour due to copigmentation were assayed. For the wines (sampled at 40, 60 and 80 storage days), the same analysis took place, as well as HPLC determination of individual anthocyanins, polyamide column extraction and HPLC determination of proanthocyanidins, proanthocyanidin separation by degree of polymerization and sensory analysis. Both woods improved colour intensity and pigment stability, which was significantly more relevant when using cherry wood, and phenolic content was consistently higher with this wood, in comparison with the control and oak wines, the latter even showing less total phenols than the control at one storage point. Both also had a considerably larger proportion of coloured anthocyanins than the control, more pronounced in the wines fermented and aged with chips, and with no discernible dominance of any wood type, and oak wood induced an increase of malvidin-3-glucoside in storage. Cherry wood also showed a much higher concentration of monomeric procyanidins, namely (+)-catechins, with a possible effect of contact time. From sensory analysis, wines aged and/or fermented with wood chips always scored highest in overall rating (CHFA at 40 storage days, CHF at 60 and OKFA at 80), significantly improving colour intensity and overall quality, as well as woody aromas, which developed more intensely in the wine fermented and aged with oak chips. There were no definite differences between contact time when using wood, and results were sometimes irregular and with considerable associated error
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Kristiono, Arie. "Wood Drying Condensate Treatment Using a Bio – Trickling Filter with Bark Chips as a Support Medium." Thesis, University of Canterbury. Chemical and Process Engineering, 2009. http://hdl.handle.net/10092/3555.
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The kiln drying of wood produces huge amounts of vapour. The vapour is released to the environment when the process purges some of the saturated hot air. The main environmental issue regarding the use of kiln drying process are the release of the water vapour which contains organic contaminants. Some of them are hazardous to human health. In addition, there are some wood particles which may released with the water vapour purging process.
In this research, the vapour is condensed and analysed for its organic contaminants and their biodegradability. The result showed that the dominant contaminants present in the condensate were ethanol and methanol with the concentration of approximately 65 mg/L and 25 mg/L respectively. The average COD concentration of the condensate was 159 ± 40 mg/L. The analysis also showed that the contaminants were biodegradable.
In order to treat the wastewater, a trickling filter process using bark chips as a support medium was used to treat an artificial wastewater. The artificial wastewater contained the dominant contaminant present in the wood drying condensate. In the experiment, different sizes of bark chips were used. In addition, the loading rate of the treatment system was varied by changing the flow rate and contaminant concentration.
The 30 cm long trickling filter using bark chips varying between of 2.8 – 4 mm diameter as the support medium gave a maximum removal of 36.4 % with removal capacity of 8.34 kg COD/m³bed•day at a flow rate of 2.8 cm/min and average inlet COD load of 20.4 kg COD/m3bed•day. The trickling filter with bark chips varying between 5.6 – 8 mm diameter as the support medium was operated using variations in contaminant concentration and flow rate. The operation using different inlet concentration gave the highest removal rate of 13.5 kg COD/m3bed•day at average initial load of 84.9 kg COD/m³bed•day, flow rate of 2.8 cm/min and theoretical initial concentration of 680 mg/L. The trickling filter operated with flow rate variation showed the highest removal rate of 10 kg COD/m³bed•day at an average inlet load of 53.3 kg COD/m³bed•day and flow rate of 7.1 cm/min.
The removal rate of the contaminants in treatment was limited. There is a number of possible explanations. First is the active surface area, which indicating the area where the contact between the biofilm surface and feed happened. The active surface area increased as the flow rate increased. Second is the residence time of the feed in the bed. The residence time of the feed varied with the flow rate. It decreased as the flow rate increased. Third is the influence of the contaminants in the feed. The presence of methanol and methanol in the feed inhibited each other’s degradation.
The dimention of a full-scale biotrickling filter to be used in actual kiln was also estimated. The estimation was made based on the maximum removal rate and optimum flow rate obtained in the experiments. The result of the estimation showed to obtain significant removal, the required bed would have to be 2.35 m in diameter and 160 in height.
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Mackinnon, Alexander J. "The effect of the composition of wood on its thermal degradation." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303294.
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Del, Galdo Vittorio. "Impact of the use of different blends of wood chips from diverse botanical species on quality parameters of white wine from Encruzado variety. A study on the effects of a different kind of wood on a white wine with no contact with lees." Master's thesis, ISA/UL, 2018. http://hdl.handle.net/10400.5/17935.
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Mestrado Vinifera Euromaster - Viticulture and Enology - Instituto Superior de AgronomiaThe aim of this study was to assess the influence of blends of wood from different botanical species in a white wine from Encruzado variety; the botanical species used in this study were French oak (Quercus peatraea), American oak (Quercus alba) and Cherry (Prunus avium) during a 60 days maceration period, with sampling done after 15, 30 and 60 days. The blends were obtained by combining 2 woods species in a ratio of 1:1, obtaining 3 blends; that is, Cherry and American oak (Ch+Am), French and American oak (Fr+Am), and Cherry and American oak (Ch+Am). In addition to these treatments 3 Control treatments were created by adding single wood of Cherry (CCh), American oak (CAm) and French oak (CFr), moreover a treatment without wood was kept (C). The amount of wood used was the same for all the treatments, that is 0,5 g/l. on the different sampling days were run both sensory analysis, by a panel of judges, evaluating aroma and taste parameters, and chemical analysis, that is, total phenols, non flavonoids and flavonoids phenols, color evolution, maderization test and tanning power. At the end of the experiment statistical analysis showed relevant data in almost all the analysis, for the chemical analysis cherry showed the highest level of total phenols and flavonoids, which is reflected also in the blends with other woods, while the French oak and its blends showed significant levels of non flavonoids phenols. The browning potential showed an decrease in wines in contact with wood except for CCh, while tanning power showed an increase in all the wines in contact with wood with the blend of cherry and American being the highest tannicity. In the sensory analysis we can observe how the global appreciation of the wines decrease with increasing maceration period with the wood both for the taste and aroma parameters, with C being the most appreciated wine at the last sampling, while the sampling of 15 and 30 days shows the wine with cherry and with American oak showing the highest values
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Tan, Ah Goh. "The combustion of wood, mainly as assessed by fluidised-bed differential thermal analysis, with particular reference to rubber wood." Thesis, University of Canterbury. Chemical and Process Engineering, 1986. http://hdl.handle.net/10092/7729.
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The combustion characteristics of Rubber wood were studied using differential thermal analysis (DTA) carried out in fluidised-beds. Test samples up to 10 mm in diameter and fluidising gas of different oxygen concentrations were used. A number of tropical hardwoods were included in the study for comparison. Prior to the above study, investigations on the thermal behaviour of Rubber wood in an inert environment, in particular, the effect of particle size, were carried out. The particle sizes used ranged from smaller than 150 mesh to 19 mm diameter.
The yields of the various degradation products and the temperature range within which they were formed were noted. The liquid and gaseous products were analysed, the former qualitatively (by proton and ¹³C NMR spectroscopy) and the latter quantitatively (by GLC).
Thermogravimetric analyses of the test materials were performed in both inert and oxidative environments to provide information complementary to those obtained from DTA, in particular, char yield and burning time in a stationary bed.
The ash contents of the wood species under study were determined. The adverse effect of ash on wood combustion was demonstrated in combustion experiments carried out in a down-draught incinerator using 5 cm thick blocks. Besides Rubber wood, three other species were used, including radiate Pine.
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Wiinikka, Henrik. "High temperature aerosol formation and emission minimisation during combustion of wood pellets /." Luleå : Luleå University of Technology, 2005. http://epubl.luth.se/1402-1544/2005/18.
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Valmari, Tuomas. "Potassium behaviour during combustion of wood in circulating fluidised bed power plants /." Espoo [Finland] : Technical Research Centre of Finland, 2000. http://www.vtt.fi/inf/pdf/publications/2000/P414.pdf.
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Ward, Courtney E. "ASSESSING NEAR-FIELD OUTDOOR CONCENTRATION VARIABILITY FROM RESIDENTIAL WOOD SMOKE COMBUSTION SOURCES." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/122.
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ABSTRACT Assessing Near-Field Outdoor Concentration Variability from Residential Wood Smoke Combustion Sources Courtney Ward The primary goal of this research was to determine whether near field effects from residential wood smoke emissions have a significant impact on acute and/or average PM2.5 concentrations, and therefore health risks. To this end, three primary research objectives were addressed: (1) measurement of the variability of wood smoke concentrations within a residential neighborhood with wood smoke sources, (2) establishment of whether the magnitude of near-source contributions to exposures can be estimated using typically available data, and (3) prediction of wood smoke concentrations using linear regression techniques on meteorological parameters.
This project was divided into 4 primary tasks. Neighborhood Selection (Task 1), Detailed Sample Plan and Method Validation (Task 2), Field Study to deploy equipment and personnel to the study area (Task 3), and Data Analysis (Task 4). The data analysis was divided into three sections: (1) evaluation of aethalometer black carbon (BC) variability, (2) regression and correlation analyses between meteorological factors and aethalometer BC, and (3) evaluation of the Personal Environmental Monitor (PEM) BC variability.
BC concentrations, as measured by aethalometers, showed that near-source contributions to average concentrations varied widely within the 1 km2 study area, with measured BC differences up to 3.27 &#;g/m3 which corresponds to an estimated PM2.5 concentration ranging from 54.5 to 81.75 &#;g/m3. Consequently, BC concentrations, and therefore exposures, are dependent upon the location within a residential area and cannot be estimated well using measurements from a single location. Based on the results from this study, it is recommended that the standard method of measuring PM2.5 should be updated by either placing additional monitors throughout the region or estimating the variation of PM2.5 using meteorological data and an understanding of the factors leading to near source variability.
PEMs’ BC measurements also showed that near-source contributions to average wood smoke concentrations vary widely over relatively short distances. Based on the BC variations between the eight to twelve monitored locations, it is unreasonable to assume that the BC measurements, and hence wood smoke PM2.5, are constant over a residential area. The maximum PEM BC difference of 0.76 &#;g/m3, or a PM2.5 concentration of 12.7 to 19.0 &#;g/m3 (depending on the BC/ PM2.5 fraction), could result in inappropriate measures being taken to protect the health of local residents. This research showed significant concentration variability associated with wood smoke burning within a residential neighborhood, with an average standard deviation of 0.10 &#;g/m3 and a relative standard deviation of 77.2%. Since these average standard deviations and ranges of PEM BC concentration variability were calculated in Cambria, these BC/PM2.5 fractions can only be applied to Cambria, in particular, the 1 km2 study area. Given the BC concentration differences between each PEM measured in the residential study area and the Cambria Fire Station, ranging from 0.09 to 0.45 &#;g/m3, it is evident that the central monitoring station is not a reasonable proxy for the average wood smoke concentrations to which people are exposed.
Using meteorological data to estimate PM2.5 concentrations from residential wood smoke is difficult because it requires knowledge the number of homes burning, distance from burners, wind speed, inversion conditions and other parameters that have spatiotemporal variability. The multiple regression analysis between the meteorological predictors and BC concentration did not detect a significant correlation for any of the meteorological factors or burning conditions. The correlation between meteorological factors and BC concentration was weak because the meteorological data was unlikely representative of the true conditions within the study area, and a lack of repeatable meteorological conditions between IOPs. Based on the meteorological data collected for the IOPs, wind directions and speeds varied considerably from 6 to 9 p.m., between IOPs, with wind directions coming from all directions and surface inversions occurring during half of the IOPs.
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Sundberg, Peter. "Implication of pellet quality on combustion performance." Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83989.
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Quality aspects of wood pellets and their use have been of utmost importance since the development of the pellet market in the early 1980s. Research and hard-earned knowledge have resulted in advancements in the field, but there are still uncertainties in the pellet industry about how different quality aspects affect combustion performance. The focus of this work has been on pellet quality, with investigations divided into three main topics: (1) the effect of physical properties of pellets on their combustion properties, (2) the effect on particle emissions due to manipulation of the ash chemistry by means of additives and, (3) how radio frequency identification (RFID) technology can be used to achieve traceability of bulk pellets. In the literature it is not clear how physical pellet quality parameters affect the combustion behavior. To gain knowledge regarding the perception of pellet quality in practice, interviews with pellet industry representatives were made initially. This was followed by detailed combustion experiments to investigate how the key quality parameters moisture content, density, and durability affect the ignition behavior and the conversion time. A large number of well-defined pellet samples produced from four different raw material mixes were used. The results showed that during stable combustion conditions, i.e., high temperature and sufficient air supply in a fully functioning combustion system, these parameters have little practical influence on the combustion performance. However, the results from the detailed laboratory experiments indicated that the choice of raw material can have a more profound effect on both ignition behavior and conversion rates, although the full-scale tests indicated that this was of little practical importance. Fuel design, i.e., choosing fuels or making adjustments to the fuel based on ash composition, can be used to lower particle emissions. This concept was demonstrated during combustion tests that were performed in three individual campaigns in medium- to large-scale boilers, 200 kWth, 2 MWth and 4 MWth respectively. In the campaigns, peat was utilized to alter the ash transformation reactions, reducing the emission of particulate matter less than 1 micron (PM1) during combustion of woody biomass, while keeping the slag formation at a manageable level. This was achieved by designing fuel blends of woody biomass with carefully selected Scandinavian peats rich in Si, Ca, and S. In one of the campaigns, softwood-based stemwood pellets were co-pelletized with different additions of peat (5 and 15 wt %) before combustion. In the other campaigns, peat was added as a separate fuel feed to Salix chips (15 wt % peat) and softwood-based stemwood pellets (10 and 20 wt % peat). The results showed that, no matter how peat was added to the fuel, the fuel design approach provided PM1 reductions of between 30 - 50 % for all fuel blends. The PM1 reduction could be achieved without causing operational problems due to slagging in any of the three commercial boilers used, although an expected increased slagging tendency was observed. RFID systems are used today for the tracking of well-defined entities; i.e., the RFID tag is linked to an object - a container, a person etc. While RFID technology has been used in this way in the energy sector to monitor biofuel transport to and from transshipment sites and energy plants, it is not known to have been used for tracing bulk biofuels, i.e. a fuel that cannot be seen as a stand-alone entity. To demonstrate the potential of using RFID technology to trace bulk fuel transportation, three tests were performed. RFID tags were placed together with biomass pellets before being conveyed through a distribution chain, from pellet producer to combustion plant. The two first tests were large-scale trials to investigate if specific RFID tags could be correlated to a specific fuel when fed into the furnace. The third test was performed to see how RFID tags distributed over time in a logistics chain. The results showed that it is possible to trace a bulk biofuel flow using RFID technology, from production site to furnace, although care must be taken to optimize the method, such as using an appropriate number of tags.
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Rau, John Anthony. "Residential wood combustion aerosol characterization as a function of size and source apportionment using chemical mass balance modeling /." Full text open access at:, 1986. http://content.ohsu.edu/u?/etd,107.
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Aulakh, Jaspreet Gallagher Thomas Vincent. "Implementing residue chippers on harvesting operation for biomass recovery." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Forestry_and_Wildlife_Sciences/Thesis/Aulakh_Jaspreet_37.pdf.
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Win, Kaung Myat. "Emissions from realistic operation of residential wood pellets heating systems." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-29582.
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Emissions from residential combustion appliances vary significantly depending on the firing behaviours and combustion conditions, in addition to combustion technologies and fuel quality. Although wood pellet combustion in residential heating boilers is efficient, the combustion conditions during start-up and stop phases are not optimal and produce significantly high emissions such as carbon monoxide and hydrocarbon from incomplete combustion. The emissions from the start-up and stop phases of the pellet boilers are not fully taken into account in test methods for ecolabels which primarily focus on emissions during operation on full load and part load. The objective of the thesis is to investigate the emission characteristics during realistic operation of residential wood pellet boilers in order to identify when the major part of the annual emissions occur. Emissions from four residential wood pellet boilers were measured and characterized for three operating phases (start-up, steady and stop). Emissions from realistic operation of combined solar and wood pellet heating systems was continuously measured to investigate the influence of start-up and stop phases on total annual emissions. Measured emission data from the pellet devices were used to build an emission model to predict the annual emission factors from the dynamic operation of the heating system using the simulation software TRNSYS. Start-up emissions are found to vary with ignition type, supply of air and fuel, and time to complete the phase. Stop emissions are influenced by fan operation characteristics and the cleaning routine. Start-up and stop phases under realistic operation conditions contribute 80 – 95% of annual carbon monoxide (CO) emission, 60 – 90% total hydrocarbon (TOC), 10 – 20% of nitrogen oxides (NO), and 30 – 40% particles emissions. Annual emission factors from realistic operation of tested residential heating system with a top fed wood pelt boiler can be between 190 and 400 mg/MJ for the CO emissions, between 60 and 95 mg/MJ for the NO, between 6 and 25 mg/MJ for the TOC, between 30 and 116 mg/MJ for the particulate matter and between 2x1013 and 4x1013 /MJ for the number of particles. If the boiler has the cleaning sequence with compressed air such as in boiler B2, annual CO emission factor can be up to 550 mg/MJ. Average CO, TOC and particles emissions under realistic annual condition were greater than the limits values of two eco labels. These results highlight the importance of start-up and stop phases in annual emission factors (especially CO and TOC). Since a large or dominating part of the annual emissions in real operation arise from the start-up and stop sequences, test methods required by the ecolabels should take these emissions into account. In this way it will encourage the boiler manufacturers to minimize annual emissions. The annual emissions of residential pellet heating system can be reduced by optimizing the number of start-ups of the pellet boiler. It is possible to reduce up to 85% of the number of start-ups by optimizing the system design and its controller such as switching of the boiler pump after it stops, using two temperature sensors for boiler ON/OFF control, optimizing of the positions of the connections to the storage tank, increasing the mixing valve temperature in the boiler circuit and decreasing the pump flow rate. For 85 % reduction of start-ups, 75 % of CO and TOC emission factors were reduced while 13% increase in NO and 15 % increase in particle emissions was observed.
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Bari, Md Aynul [Verfasser]. "Investigation of Particulate Matter Originating from Wood Combustion in Residential Areas / Md. Aynul Bari." Aachen : Shaker, 2009. http://d-nb.info/115983282X/34.
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Brýdl, David. "Dřevokompozity s alkalicky aktivovanou popílkovou matricí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225718.
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This thesis examines the possibility of creating composite mainly from waste materials. The matrix of this composite was prepared from fly ash type F, which was activated by sodium water glass. Wood chips were used as a filler. This thesis includes theoretical and experimental parts. The theoretical part deals with the most important issues of wood composites with an inorganic matrix as well as basic components of investigated composite, ie alkaline activated fly ash and wood. In the experimental part, the fly ash pastes were prepared, from which the most suitable mixture was chosen for the composite preparation. Properties of wood composite with alkali activated fly ash matrix were investigated depending on the dose of wood chips.
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Muchai, Jesse G. "Design and operational characteristics of a gasification-combustion process : flammability model /." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-03042009-040746/.
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Yurdakul, Yorulmaz Sema. "Investigation Of Emissions And Combustion Kinetics Of Waste Wood Samples With Thermal And Spectral Methods." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607570/index.pdf.
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The mechanisms and kinetics of combustion of waste wood as well as the phases during combustion processes are important to eliminate these wastes without any possible damage to environment. In the present study, combustion mechanisms, activation energy and pre-exponential constants, and phases of combustion were investigated for untreated natural pine and treated Medium Density Fiberboard (MDF), plywood and particleboard samples that involve some chemicals and additives. Waste wood samples were heated in air at 10, 20 and 30oC/min heating rates in a Thermo Gravimetric Analyzer (TGA) from room temperature to 900oC. Thermogravimetry (TG) and Derivative Thermogravimetry (DTG) curves for all samples were obtained. The gases formed during combustion reactions were directly fed to a Fourier Transform Infrared Spectroscopy (FTIR) instrument coupled to TGA. Emission characteristics of the samples were determined in-situ by using the FTIR spectrums.
As a result of TG analysis, thermal decomposition of treated samples was observed at lower temperatures as compared to the untreated pine sample because of the catalyzing effects of the chemicals in the treated samples.
Therefore, there were less flammable products, lower weight losses in the main oxidation region, decrease in the max. weight loss temperatures and formation of more char for treated samples as compared to untreated pine sample. In other words, chemicals used during production of these samples lead to decrease in the combustibility of the treated samples.
Thermal kinetic constants for the samples were calculated by using Coats Redfern and Broido Methods. In order to find out the mechanisms responsible for the oxidation of the waste wood samples in different regions, six solid state mechanisms of Coats Redfern Method were tested.
As a result of FTIR analysis of the emitted gases from TG analysis, several chemical groups were detected from pine and treated samples. Combustion of all samples revealed some gases containing aromatics, C-H groups, CO2 and CO. However, there were some toxic and carcinogenic gases like formaldehyde, isocyanate group, ammonia, phenyl group and benzoylbromide among the emissions of treated samples which need utmost attention when recovering energy from treated waste woods.
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Gutiérrez, Iris Raquel [Verfasser]. "Toxicity Screening of Wood Combustion Fine Dust Using a Microbial Test Battery / Iris Raquel Gutiérrez." Konstanz : Bibliothek der Universität Konstanz, 2014. http://d-nb.info/1049892852/34.
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Peterson, Mackenzie. "The Effect of the Antecedent Dry Conditions on Nitrogen Removal for a Modified Bioretention System." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6567.
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Eutrophication is defined as the ‘over enrichment’ of a water body from nutrients, resulting in uncontrolled growth of primary producers, leading to periods of oxygen depletion from decomposition of the algal organic matter. According to the 2010 Water Infrastructure Needs and Investment (a U.S. Congressional Report), 40% of U.S. water bodies are contaminated with pollutants, including nutrients. Non-point sources of nutrient pollution are a major cause of this reduction in water quality. One way to decrease eutrophication is to manage nutrients found in stormwater runoff, before they reach a receiving water body.
Bioretention cells containing an internal water storage zone (IWSZ) have been shown to remove higher amounts of nitrogen than conventional cells (without an IWSZ). The IWSZ contains an organic carbon substrate, usually derived from wood chips submerged in water, which supports the biochemical process of denitrification. Characteristics of wood chips that affect nitrogen removal include carbon content (%), leaching of dissolved organic carbon (DOC), and wood chip size and type. However, there is limited information on how the intermittent hydraulic loading that is associated with these field systems impacts their performance. Accordingly, the overall goal of this research is to improve understanding of the effect that the antecedent dry conditions (ADC) have on the performance of a field scale bioretention cell modified to contain an IWSZ.
The nine different types of wood chips used in laboratory and field studies identified in the literature were categorized as hardwood and softwood. Literature showed that total organic carbon (TOC) leached from softwood chips is almost double the TOC measured from the hardwood chips, 138.3 and 70.3 mg/L, respectively. The average observed nitrogen removal for softwood chips was found to be greater than the removal for the average of the hardwood chips (75.2% and 63.0%, respectively). Literature also suggests that larger wood chip size may limit the availability of the carbon for the denitrifying organisms and provides less surface area for the biofilm growth.
A field study conducted for this research compared the performance of a modified bioretention system designed to enhance denitrification, addition of an IWSZ, with a conventional system that does not contain an IWSZ. Fourteen storm events were completed from January 2016 to July 2016 by replicating storm events previously completed in the laboratory using hydraulic loading rates (HLR) of 6.9 cm/h, 13.9 cm/h, and 4.1 cm/h. The goal was to have results from storm events with ADCs of two, four, and eight days, with the varying durations of hydraulic loading of two, four, and six hours. Synthetic stormwater, simulating nitrogen levels common in urban runoff, was used as the system’s influent to assist in running a controlled experiment. The resultant ADCs ranged from 0 to 33 days, with the average ADC being 9 days. The fourteen sets of influent samples were averaged to obtain mean influent concentrations for the synthetic stormwater. These values were used when calculating the percent nitrogen removal for the four measured nitrogen species (NOx – N, NH4+– N, organic N, and TN).
The field storm events were separated into three groups based on HLR and duration to eliminate the affects of both variables on nitrogen removal for these results, since the focus is the ADC. For the low HLR (4.1 cm/hr), there were four storm events (ADCs of 4 to 33 days), as the ADC increased, greater percentages of ammonium – nitrogen, organic nitrogen, and total nitrogen were removed. For nitrate/nitrite – nitrogen, the percent removal was rather consistent for all four storm events, not significantly increasing or decreasing with changes in the ADC. There were five storm events (ADCs of 0 to 28 days) tested with the median HLR (6.9 cm/hr), nitrogen removal for all four species increased as the ADC increased. The increase was significant (p0.05) for nitrate/nitrite – nitrogen. The third group also contained five storm events (ADCs from 0 to 11 days) that were tested with the highest HLR (13.9 cm/hr). Ammonium – nitrogen, nitrate/nitrite – nitrogen, and total nitrogen all increased with the ADC, and organic nitrogen removal decreased with the increasing ADC. As a result, this research concluded that the difference in HLR affects the nitrogen removal efficiency, but overall increasing the ADC increased nitrogen removal for NOx – N, NH4+ - N, organic N, and TN.
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Santos, Filipa Ferreira Reis Cardoso dos. "Use of alternative wood chips from new botanical species. Their impact on phenolic composition and sensory properties of a rose wine from Touriga Nacional grape variety." Master's thesis, ISA, 2017. http://hdl.handle.net/10400.5/14854.
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Mestrado em Viticultura e Enologia / Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do PortoThe aim of this study was to evaluate the effects that acacia (Robinia pseudoacacia), cherry (Prunus avium), American and French oak (Quercus alba and Quercus petraea) wood chips and the evolution of the phenolic composition and sensorial properties of a rose wine made from Touriga Nacional grape variety during a storage period of 20 days. Chemical analysis were carried out: total phenols, flavonoid and non-flavonoid phenols, chromatic characteristics and tanning power. At the end of the assay a sensory analysis was performed. Three sensorial parameters group were considered: aspect, aroma and taste. The results showed some statistical significant differences in most of the phenolic parameters, mainly in the wines without fining. Thus, it was possible to conclude that there are differences between the impact of different botanic species used. In particular, acacia wood chips thus, the results suggest a significant impact on phenolic content of rose wine during the short period of stage, by the use of acacia wood chips. Concerning to sensorial analysis, two situations could be observed: a slight preference for the wine treated with cherry wood chips – without fining. On the other hand, there was a slight preference for the control wine (without added wood) – after fining
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Paulrud, Susanne. "Upgraded biofuels-effects of quality on processing, handling characteristics, combustion and ash melting /." Umeå : Unit of Biomass Technology and Chemistry, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a449.pdf.
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