Twenty-eight beef-type animals were divided into four groups and fed four rations consisting of equal amounts of basal ration, to which increments of alder sawdust (Alnus rubra) were added (0, 13%, 21%, and 35%) (Experiment I). The addition of the sawdust had no significant effect on total gain although the three groups of animals receiving sawdust in their diet had a higher rate of gain than the group receiving no sawdust. The effects of the ration on the carcass grade and the acceptability (tenderness and juiciness) of the meat as studied by a trained taste panel, were non-significant. When the rations used in the above trial were subjected to a digestion trial using mature wethers, the results coincided with the growth data collected from the steers used above. If the digestion of the basal rations were taken as constant, the wood material had a digestion coefficient ranging from 46.5% to 13.5%, depending on the level of sawdust in the diet. It was felt that a figure of 13% digestion for sawdust was close to being correct, and that the variation in measurement of the digestion of sawdust was due to the increased utilization of the basal ration when the sawdust was present. Analysis of the rumen fluid of the steers in the growth trial for total and individual volatile fatty acids (VFA) showed a decrease (p<.05) in the molar percent of propionic acid as the level of wood in the diet increased, while the total concentration of VFA and the molar percent acetic acid remained relatively constant. Thirty-six yearling Hereford steers, assigned to six treatments consisting of a basal ration and three roughage sources (hay (H), alder sawdust (W), and extruded alder sawdust (E)), fed at two levels (15% and 20%), were used in a study to determine the effect of heat and pressure treatment of wood on the utilization. The growth of the animals on the H rations was significantly (p< .01) greater than those on the other treatments. The effect of treating the sawdust by extruding it was non-significant although the animals on the extruded wood diet had a slight increase in gain over those on the W ration. The effect of level of roughage was nonsignificant. The effects of level of protein in the diet and the interaction with roughage source were studied. Protein levels of 13% and 15% were studied, along with two roughage sources (hay (H), and alder sawdust (W)), fed at two levels (15% and 20%). The H rations again had a significantly (p<.01) greater gain. The effect of increasing the protein level in the diet was found to be non-significant. When the above rations were subjected to analysis using the in vitro technique, results showed that the H rations had a significantly (p < .01) higher digestion than either the W or E rations. It was also found that the E rations had a higher digestion coefficient than the W rations (p <«05). Increasing the roughage level from 15% to 20% caused a significant (p<.01) decrease in digestion. When the same rations were subjected to an in vivo digestion study using growing wethers, the results were similar to the in vitro study with the H rations having a greater digestion (p <.01) than the W or E rations. However the difference between the W and E rations was non-significant. An equation for predicting the in vivo dry matter digestion is given: In vivo dry matter digestion = 60.1252 + 0.0221 (in vitro dry matter digestion) + 0.4799 (acid detergent fibre) - 3.5855 (lignin) - 0.8395 (cellulose). / Land and Food Systems, Faculty of / Graduate

As placas de madeira aglomerada, amplamente empregadas para fabricação de móveis, estão consolidadas no mercado, mas merecem especial atenção devido ao seu alto custo quanto aos adesivos empregados e principalmente à vulnerabilidade à umidade se caso entre em contato com a mesma. Diante os fatos, este trabalho apresenta uma nova alternativa de adesivo, empregado por meio de aparas de isopor (EPS), largamente encontrados como resíduos, e o mesmo, ao envolver as partículas de madeira, material também empregado para a fabricação dos painéis, o torna apto para emprego em ambientes ligados diretamente à umidade, sejam eles internos ou externos à edificação. Com isso, o presente trabalho apresenta a elaboração e a proposta de utilização de um novo produto em forma de painel de madeira, produzido com serragem residual de serrarias, como partículas, e EPS (isopor) dissolvido, como adesivo, que possam ser empregados também na construção civil. Assim, foram produzidos painéis com quatro espécies de resíduos de madeira: pinus, eucalipto, teca e peroba. De cada uma das amostras, foram confeccionados dez painéis para a avaliação das características física, mecânica e outros ensaios. Dos resultados de caracterização física, pode-se concluir que os painéis estão conforme padrões exigidos pela norma brasileira NBR 14.810-2 - \"Chapas de madeira aglomerada\" da ABNT (2006b), e, devido aos baixos valores de inchamento, são adequados à utilização em ambientes úmidos e/ou externos. Dos resultados de caracterização mecânica, os painéis apresentaram bons resultados quanto à ligação interna e compressão, indicando ser promissor o uso de isopor como adesivo bem como sua utilização atrelada a painéis de fechamento. Entretanto, como os resultados de flexão estática não foram satisfatórios, prova-se que tais painéis não podem ser solicitados estruturalmente. Quanto aos outros ensaios realizados, todos os resultados foram favoráveis e, se utilizados conforme especificações técnicas, tornam-se coerentes para empregos em edificação. Como resultado, observou-se que os painéis podem ser produzidos e utilizados no mercado da construção civil, certificando que o produto pode ser empregado de forma segura, desde que sejam conhecidas suas funções, tempo de uso e manutenções necessárias. Desta forma, pretende-se contribuir para a produção e a análise de novos materiais que possam colaborar com a melhoria ambiental. / The particleboards, which are widely employed to manufacturing furniture, are established in the market, but they deserve a special attention due to their high cost considering the adhesives used on them and, paramountly, due to their vulnerability to humidity if on contact with their own parts. Facing the facts, this work presents a new alternative adhesive, applied with Styrofoam trims (EPS), usually found as residues, it may be used for involving the particles of wood, which are also used for manufacturing of the panels, and it makes it suitable for the use in environments directly related to humidity, whether it is internal or external to the building. Therewith, this work introduce the explanation and the proposition of the use of a new product in the shape of wood panel, produced with residual sawdust from sawmills, as particles and the EPS (Styrofoam) dissolved as an adhesive, which might also be used in construction. So, panels have been produced with four kinds of residual wood: pine, eucalyptus, teak and peroba. From each one of the samples, it has been manufactured ten boards for the evaluation of the physical and mechanical characteristics and other tests. From the results of physical description, it may be concluded the panels are in conformity with the requirements of the Brazilian standard NBR 14810-2 - \"Particleboards\" from ABNT (2006b), and due to low swelling values are appropriate to use it in humid and or outdoor environments. The results of mechanical description, the panels have shown satisfying results as for the internal connection and compression, indicating it is promising the use of Styrofoam as an adhesive and also its use in cable management panels. However, since the results of the static bending were not sufficient, it is proved such panels cannot be ordered, structurally. As for the other tests, all the results were positive and if they were used according to the technical specifications, they would become consistent for the application in construction. As a result, it was observed the panels might be produced and used in the market of construction, confirming the product may be applied safely as long as their functions are recognized, useful life, and required maintenance. In this way, it is intended to contribute to the production and analysis of new materials which may collaborate to improvement of the environment.

A gas-fluidized bed bioreactor was developed in this research as a new method for treating polluted air. The fluidization characteristics of selected packing materials were investigated. Then, bioremediation was tested using two types of packing in a fluidized bioreactor, as well as in a comparable packed bed. Microorganisms on the particles biodegrade contaminants in the polluted air, which flows up through the bed. At high flowrates, the polluted air fluidizes the particles, while at low velocities the operation is in packed bed mode.<p>Initially, sawdust was selected for use as a packing material. Due to the poor fluidization properties of sawdust, glass spheres were added. A mixture of sawdust and glass spheres remained well mixed during fluidization. In the mixture, interparticle forces increased with increasing moisture in the sawdust, eventually causing defluidization of the bed. In the absence of bioremediation, mass transfer was studied between ethanol-contaminated air and sawdust/glass sphere packing, and found to be higher in the fluidized versus packed mode. In bioremediation experiments, ethanol removal efficiencies were as high as 95% in both operating modes. The maximum elimination capacities (EC) of ethanol were 75 and 225 g m^-3 sawdust h^-1 in the fluidized and packed beds respectively.<p>The packing of the fluidized bed bioreactor was optimized in order to boost bioremediation rates. Experiments showed that peat granules fluidized well in a bubbling regime, likely due to their relatively high density and sphericity. In peat bioremediation trials, the fluidized mode outperformed the packed bed; the maximum ECs were 1520 and 530 g m^-3 peat h^-1, respectively. Removal efficiency in the fluidized mode decreased with velocity, because the size and amount of large bubbles increased.<p>A steady-state model of the fluidized bioreactor was developed. By taking account of bubble properties during fluidization, the model helps to explain how bubble size, microbial properties and bioreactor residence time affect removal efficiency and elimination capacity of the bioreactor.<p>A peat gas-fluidized bioreactor shows promise as an efficient, low-cost technology for air treatment. Particle mixing in the fluidized bed may prevent operating problems associated with the packed bed bioreactor. Fluidized bioreactors are ideal for the treatment of high volume, low concentration air emissions.

Biomassa är en växande energikälla i samhället. Biomassa så som sågspån behöver ofta torkas och pelleteras innan det kan användas som energikälla vid förbränning. Sågspån torkas innan pelleteringen för att kunna ge ett bra värmevärde och för att kunna förbrännas utan ökade halter av utsläpp. I takt med ökad användning av detta bränsle finns det en ökad efterfrågan på energieffektiva torkningsmetoder. På Karlstad Universitet har det därför byggts en pilotanläggning av en pneumatisk tork med syfte att fungera som ett steg i en energieffektiv torkningsmetod kallad ”Two Step Drying Technique” eller TSDT. Det här arbetet har handlat om att utvärdera effektivitetsmått och driftinformation för torken på Karlstads Universitet. Torken har fått namnet PD-KaU som står för ”Pneumatic Dryer at Karlstad University”. Genom praktiska mätningar av PD-KaU:s prestanda vid torkning av sågspån med uppvärmd luft har effektivitetsmåtten  och  beräknats vid olika driftfall. Även skillnader i torr- och våttemperaturer i olika delar av torken har utvärderats. En effektbalans har använts för att kontrollera mätningarnas stabilitet. De olika driftfallen fås genom variation av torkningsparametrar så som mängden sågspån som torkas, ca 1 och 2 kg torrsubstans per minut, och variation av luftens temperatur, 80, 100 och 120 °C, samt hastighet genom torken, 6, 8 och 10 m/s. Även 12 och 14 m/s testades vid 80 °C. Torkens minimala fluidiseringshastighet för sågspån har beräknats och minimala hastigheten som krävs för att sågspånet ska transporteras genom torkens rörsystem har mätts. Mätningar på sågspånets fukthalter före och efter torken tillsammans med massflöden sågspån genom torken har gjorts för alla driftfall. Använd effekt från överhettare och fläkt som finns i anslutning till torken har också mätts och dessa mätningar ligger till grund för beräkningarna av  och . Med hjälp av elektronisk mätning av torra temperaturer och tryckfall över systemet har också våttemperaturer i olika delar av systemet kunnat beräknas. All data från dessa mätningar har också använts till effektbalansen. Vid massflöden på ca 1 kg/min TS sågspån genom torken är  som högst om hastigheten på luften är låg. Högsta  för de driftfall som testats vid detta massflöde fås när lufttemperaturen är 120 °C och lufthastigheten är kring 8,6 m/s. Genom öka på rörsystemets längd i torken skulle ett högre  kunna uppnås vid högre hastigheter. Vid ett massflöde på ca 2 kg/min fås högsta  vid lufttemperaturen 100 °C och lufthastighet kring 8,3 m/s. Om höga massflöden sågspån används kommer sågspånet i större grad i kontakt med luften och  är högt oberoende av lufthastigheten i de intervall som testats. Optimala lufttemperaturen visade sig vara vid 100 °C.  är som lägst vid låga hastigheter och höga massflöden. Lägsta värdet på  för båda massflödena fås när lufttemperaturen var 120 °C och lufthastigheten 7,0 m/s. Genom att minska på rörsystemets längd skulle  kunna minska. Utvärderingen av våttemperaturen visar att det mesta av torkningen sker i början av systemet. / Biomass is a growing source of energy in our society. Biomass such as sawdust often needs to be dried and pelletized before it can be burnt to produce energy. Sawdust is dried before pelleting in order to give a good calorific heat value and to be able to be incinerated without increased levels of emissions. With increased use of this fuel there is an increasing demand for energy efficient drying methods. A pilot plant of a pneumatic dryer has therefore been built at Karlstad University with a purpose to serve as a step in an energy efficient drying method called “Two Step Drying Technique” or TSDT. This thesis aimed to evaluate performance and operating information for the dryer at Karlstad University. The dryer has been named PD-KaU which stands for "Pneumatic Dryer at Karlstad University." Through practical measurements of the PD-KaU's performance when drying sawdust with heated air, efficiency indices  and  has been calculated at various operating conditions. Differences in the dry and wet-bulb temperature in different parts of the dryer have also been evaluated. An energy balance, or more correctly a power balance has been used to evaluate the stability of the measurements. The various operating conditions is obtained by variation of different drying parameters such as the amount of sawdust dried, about 1 and 2 kg solids per minute, and the variation of air temperature, 80, 100 and 120 ° C, and the speed through the dryer, 6, 8 and 10 m/s. Also, 12 and 14 m/s were tested at 80 ° C. The minimum fluidizing velocity for the dryer when using sawdust has been calculated and the minimum speed required for the transportation of sawdust through the dryer tubes have been measured. Measurements on the sawdust moisture levels before and after the dryer along with the mass flow of sawdust through the dryer have been made for all operating conditions. The power from the super heater and fan that is used with the dryer has also been measured and these measurements together with the moisture levels and mass flows are used for calculating  and. By using electronic equipment measurements of dry temperatures and pressure drop across the system has also been possible and they have been used to calculate the wet-bulb temperature in different parts of the system. All data from these measurements were also used for the power balance. At mass flow rates of about 1 kg/min solids of sawdust through the dryer  is highest if the speed of the air is low. The highest value on  for the various operating conditions at this mass flow rate was found to be at an air temperature of 120 °C and air speed of 8,6 m/s. By increasing the length of tubing in the dryer, a higher  be achieved at higher speeds. If 2 kg/min of solids are put into the system the sawdust comes in contact with the air to a greater extent and  is highly independent of the air velocity in the ranges tested. At this higher mass flow rate the highest value of  was found to be at an air temperature of 100 °C and an air speed of 8,3 m/s Optimum air temperature was found to be at 100° C.  is lowest at low speeds and high mass flows. The lowest value for  for both tested mass flow rates was found to be when the air temperature was 120 °C and the air speed was 7,0 m/s. By reducing the tubing length SPC could be reduced. The evaluation of the wet-bulb temperature shows that most of the drying takes place in the beginning of the system.

A gas-fluidized bed bioreactor was developed in this research as a new method for treating polluted air. The fluidization characteristics of selected packing materials were investigated. Then, bioremediation was tested using two types of packing in a fluidized bioreactor, as well as in a comparable packed bed. Microorganisms on the particles biodegrade contaminants in the polluted air, which flows up through the bed. At high flowrates, the polluted air fluidizes the particles, while at low velocities the operation is in packed bed mode.<p>Initially, sawdust was selected for use as a packing material. Due to the poor fluidization properties of sawdust, glass spheres were added. A mixture of sawdust and glass spheres remained well mixed during fluidization. In the mixture, interparticle forces increased with increasing moisture in the sawdust, eventually causing defluidization of the bed. In the absence of bioremediation, mass transfer was studied between ethanol-contaminated air and sawdust/glass sphere packing, and found to be higher in the fluidized versus packed mode. In bioremediation experiments, ethanol removal efficiencies were as high as 95% in both operating modes. The maximum elimination capacities (EC) of ethanol were 75 and 225 g m^-3 sawdust h^-1 in the fluidized and packed beds respectively.<p>The packing of the fluidized bed bioreactor was optimized in order to boost bioremediation rates. Experiments showed that peat granules fluidized well in a bubbling regime, likely due to their relatively high density and sphericity. In peat bioremediation trials, the fluidized mode outperformed the packed bed; the maximum ECs were 1520 and 530 g m^-3 peat h^-1, respectively. Removal efficiency in the fluidized mode decreased with velocity, because the size and amount of large bubbles increased.<p>A steady-state model of the fluidized bioreactor was developed. By taking account of bubble properties during fluidization, the model helps to explain how bubble size, microbial properties and bioreactor residence time affect removal efficiency and elimination capacity of the bioreactor.<p>A peat gas-fluidized bioreactor shows promise as an efficient, low-cost technology for air treatment. Particle mixing in the fluidized bed may prevent operating problems associated with the packed bed bioreactor. Fluidized bioreactors are ideal for the treatment of high volume, low concentration air emissions.

Mass transport of chemicals into wood is important in kraft pulping. This thesis models small wood particles as cylinders and monitors how tritiated water and sulfide diffuse into the water-filled pores. Tritiated water diffusion is Fickian and diffuses completely into the water contained in the wood. Tortuosity values of the aspen and pine are tabulated. As particle size decreases, the tortuosity of the particles increases. As sulfide diffuses into wood, it is occluded from some water filled areas. Charge exclusion is a possible explanation for this. Sulfide and hydroxide transport into wood chips was displayed using indicators for each component. Pictures show sulfide ingress into the chip core faster, thus confirming the diffusion results. Fractionated sawdust was pulped to determine particle size effect on cooking and pulp properties.

This report is a study on the smoldering combustion of natural sawdust from untreated woods. The objective was to develop and test an experimental technique to study the fundamental behavior of sawdust smolder. The experimental setup was an annulus cookstove packed with sawdust between the inner and outer radii creating a central hollow core. The sawdust was ignited by a heating coil wrapped around the inner radius. Thermocouples were embedded in the sawdust bed fanning out in the radial direction, and temperature was recorded throughout the smolder process. Consistent with the literature, the experimental results indicate that wood smolder consists of three pathways, 1) sawdust to char, 2) sawdust to volatiles, and 3) char to ash. Pathways 1 and 3 can be clearly characterized by the temperature profile of the smolder; however, pathway 2 often involves flaming of the sawdust and is beyond the scope of this study. Pathway 1, sawdust to char, is an endothermic reaction that results in a clearly defined char front that propagates across the sawdust bed in the radial direction. As smolder proceeds, the char continues to oxidize and breaks down into non-volatile products such as water vapor and carbon dioxide (CO₂) in further exothermic reactions. Pathway 2, char to ash, is an exothermic reaction that can lead to glowing combustion when exposed to sufficient amounts of oxygen and results in spikes in temperature. In contrast to the clearly defined char front, the ashing zone traces cracks in the sawdust where air can penetrate through, and has no discernible front. Section 1 discusses the motivation behind the study of sawdust cookstoves in third world countries, in particular Ghana, to replace wood with sawdust as a cheap alternative for household fuel. Section 2 details the experimental setup of the cookstove rig and the methodology of the experiments conducted. Section 3 reports the results of the experiments and analyzes the temperature profiles in relation to the three types of chemical reactions as noted above. Section 4 concludes with a summary of the results and discusses efforts in measuring emissions from the smolder and future work to be done. / text

As placas de madeira aglomerada, amplamente empregadas para fabricação de móveis, estão consolidadas no mercado, mas merecem especial atenção devido ao seu alto custo quanto aos adesivos empregados e principalmente à vulnerabilidade à umidade se caso entre em contato com a mesma. Diante os fatos, este trabalho apresenta uma nova alternativa de adesivo, empregado por meio de aparas de isopor (EPS), largamente encontrados como resíduos, e o mesmo, ao envolver as partículas de madeira, material também empregado para a fabricação dos painéis, o torna apto para emprego em ambientes ligados diretamente à umidade, sejam eles internos ou externos à edificação. Com isso, o presente trabalho apresenta a elaboração e a proposta de utilização de um novo produto em forma de painel de madeira, produzido com serragem residual de serrarias, como partículas, e EPS (isopor) dissolvido, como adesivo, que possam ser empregados também na construção civil. Assim, foram produzidos painéis com quatro espécies de resíduos de madeira: pinus, eucalipto, teca e peroba. De cada uma das amostras, foram confeccionados dez painéis para a avaliação das características física, mecânica e outros ensaios. Dos resultados de caracterização física, pode-se concluir que os painéis estão conforme padrões exigidos pela norma brasileira NBR 14.810-2 - \"Chapas de madeira aglomerada\" da ABNT (2006b), e, devido aos baixos valores de inchamento, são adequados à utilização em ambientes úmidos e/ou externos. Dos resultados de caracterização mecânica, os painéis apresentaram bons resultados quanto à ligação interna e compressão, indicando ser promissor o uso de isopor como adesivo bem como sua utilização atrelada a painéis de fechamento. Entretanto, como os resultados de flexão estática não foram satisfatórios, prova-se que tais painéis não podem ser solicitados estruturalmente. Quanto aos outros ensaios realizados, todos os resultados foram favoráveis e, se utilizados conforme especificações técnicas, tornam-se coerentes para empregos em edificação. Como resultado, observou-se que os painéis podem ser produzidos e utilizados no mercado da construção civil, certificando que o produto pode ser empregado de forma segura, desde que sejam conhecidas suas funções, tempo de uso e manutenções necessárias. Desta forma, pretende-se contribuir para a produção e a análise de novos materiais que possam colaborar com a melhoria ambiental. / The particleboards, which are widely employed to manufacturing furniture, are established in the market, but they deserve a special attention due to their high cost considering the adhesives used on them and, paramountly, due to their vulnerability to humidity if on contact with their own parts. Facing the facts, this work presents a new alternative adhesive, applied with Styrofoam trims (EPS), usually found as residues, it may be used for involving the particles of wood, which are also used for manufacturing of the panels, and it makes it suitable for the use in environments directly related to humidity, whether it is internal or external to the building. Therewith, this work introduce the explanation and the proposition of the use of a new product in the shape of wood panel, produced with residual sawdust from sawmills, as particles and the EPS (Styrofoam) dissolved as an adhesive, which might also be used in construction. So, panels have been produced with four kinds of residual wood: pine, eucalyptus, teak and peroba. From each one of the samples, it has been manufactured ten boards for the evaluation of the physical and mechanical characteristics and other tests. From the results of physical description, it may be concluded the panels are in conformity with the requirements of the Brazilian standard NBR 14810-2 - \"Particleboards\" from ABNT (2006b), and due to low swelling values are appropriate to use it in humid and or outdoor environments. The results of mechanical description, the panels have shown satisfying results as for the internal connection and compression, indicating it is promising the use of Styrofoam as an adhesive and also its use in cable management panels. However, since the results of the static bending were not sufficient, it is proved such panels cannot be ordered, structurally. As for the other tests, all the results were positive and if they were used according to the technical specifications, they would become consistent for the application in construction. As a result, it was observed the panels might be produced and used in the market of construction, confirming the product may be applied safely as long as their functions are recognized, useful life, and required maintenance. In this way, it is intended to contribute to the production and analysis of new materials which may collaborate to improvement of the environment.

Clean and efficient electricity can be generated using an Integrated Gasification Combined Cycle (IGCC). Although IGCC is typically used with coal, it can also be used to gasify other carbonaceous species like biomass and petroleum coke. It is important to understand the pyrolysis and gasification of these species in order to design commercial gasifiers and also to determine optimal conditions for operation. High heating-rate (100,000 K/s) pyrolysis experiments were performed with biomass (sawdust) in BYU's atmospheric flat-flame burner reactor at conditions ranging from 1163 to 1433 K with particle residence times ranging from 23 to 102 ms. Volatile yields and mass release of the sawdust were measured. The measured pyrolysis yields of sawdust are believed to be similar to those that would occur in an industrial entrained-flow gasifier since biomass pyrolysis yields depend heavily on heating rate and temperature. Sawdust pyrolysis was modeled using the Chemical Percolation Devolatilization model assuming that biomass pyrolysis occurs as a weighted average of its individual components (cellulose, hemicellulose, and lignin). Thermal cracking of tar into light gas was included using a first-order kinetic model. The pyrolysis and CO2 gasification of petroleum coke was studied in a pressurized flat-flame burner up to 15 atm for conditions where the peak temperature ranged from 1402 to 2139 K. The measured CO2 gasification kinetics are believed to be representative of those from an entrained-flow gasifier since they were measured in similar conditions of elevated pressure and high heating rates (100,000 K/s). This is in contrast to the gasification experiments commonly seen in the literature that have been carried out at atmospheric pressure and slow particle heating rates. The apparent first-order Arrhenius kinetic parameters for the CO2 gasification of petroleum coke were determined. From the experiments in this work, the ASTM volatiles value of petroleum coke appeared to be a good approximation of the mass release experienced during pyrolysis in all experiments performed from 1 to 15 atm. The reactivity of pet coke by CO2 gasification exhibited strong pressure dependence.

No description available.