Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 57-59). Also available on the World Wide Web.

Hog fuel is increasingly becoming an alternative to alleviate the energy problems associated with the use of fossil fuels. To make adequate use of hog fuel, its moisture content should be reduced prior to combustion either in an external dryer or in the initial stages of a hog fuel boiler. Therefore, this research project was undertaken to establish the factors which govern the drying rate of wet hog fuel particles. The convective drying of wood-waste on the slow moving bed of hog fuel boilers was simulated in a packed bed. The information which was obtained can also be applied to approximate the drying behaviour in external dryers. An apparatus was constructed to accommodate the use of hot air, flue gas, superheated steam and a mixture of them as drying media. Drying tests were carried out, over the temperature range of 125-245°C, on 1.1 to 4 kg batches of Western Hemlock hog fuel of thicknesses from 2 to 12 mm. The relative effects of velocity (V), temperature (T), nature of the drying gas, bed depth (L), and initial moisture content of the hog fuel samples (M₀) on the drying process were investigated using a mixture of several thickness fractions having an average (sauter mean) particle thickness (dp) of 6.3 mm. Drying rates were determined through measurement of the change either in humidity of the drying gas, or flow rate of the superheated steam across the bed of hog fuel. Gas humidity was measured using an optical dew point sensor and steam flow was monitored using an orifice plate connected to a massflow transmitter. Drying rates have been quantified as functions of hog fuel particle thickness, initial moisture content and bed depth. The effects of gas temperature, velocity and humidity have also been quantitatively established. The drying process was insensitive to CO₂ content of the drying gas. The existence of an inversion temperature above which drying rates increase with humidity of the drying medium was both experimentally and theoretically confirmed and the locus of inversion points was determined. Instantaneous normalized drying rates, ƒ, and characteristic moisture contents, Φ , have been determined and the existence of a unified characteristic drying rate curve was verified. Using a receding plane model, ƒ was formulated as a function of Φ, for dp = 6.3 mm and at L = 25 cm, for both superheated steam and relatively dry air. Pressure drop measurements were obtained for all the runs with the exception of the superheated steam ones. Application of an accepted pressure drop equation permitted the sphericity of the hog fuel particles to be approximated. A design equation for gas pressure drop in beds of hog fuel particles was investigated. The simultaneous heat and mass transfer processes in drying during the heat transfer controlled period was studied. Using the concept of volumetric evaporation, an empirical correlation for the overall heat transfer coefficient in a packed bed of hog fuel particles has been obtained. The effects of different parameters on both the particle residence time required for drying and the grate heat release rate in hog fuel boilers were determined. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

A long-term project was initiated in order to stuq the et!ecta of sawdust Jlltll.ch and two .forms of a synthetic soil conditioner on the yield of vegetable crops. Data is in this thesis concerning experimental results of two years, 1953 and 1954. In addition, a report is given on a preliminary study which was conducted in 1952. In general, not enough research has been done on this project to formulate definite conclusions. However, certain tr.nds are apparent: 1. The soil treatments have caused no significant changes in the pH values of the soil. 2. The treatments have caused no wide fluctuations in the amounts of calcium, magnesium, phosphoric acid, or potash in the soil. 3. The potassium dichromate and sulphuric acid tests, used by the Soils Laboratory of this institution, did not indicate that the soil treatments increased the organic matter content of the soil. 4. In general, synthetic soil conditioners as used in this test have produced no significant effects. 5. Incorporation of sawdust into the soil mq result in nitrate deficiency. However, this deficiency can be readily corrected by the addition or fertilizers containing nitrogen. 6. Sawdust mulch has, in general, benefitted the production of vegetable crops. The beneficial effects are probably caused by conservation of soil moisture (including an increase in the percentage of moisture available to plants), and by reduction of soil temperature fluctuations. / Master of Science

The objective of this research was to test a prototype sawdust dryer designed by Arrowhead Forest Products, a wood products firm based in St. Louis. The dryer is designed to be used by small to medium sized sawmills and pallet mills. A series of 50 one hour or longer trials were conducted to develop operating parameters and test the sensitivity of the dryer performance to species, operating speed, throughput rate and Xi atmospheric conditions. Performance criteria measured included moisture content removed, final moisture content and pounds of water removed per hour in the entire system and the individual system components. Performance measures were developed from 30 one kilogram sawdust samples collected during each trial. The sampling procedure paired samples pulled with temperature profiles across the dryer and ambient weather conditions. Analysis of variance and analysis of covariance were used to explore relationships and interactions between the variables of interest. The system proved capable of removing 10% to over 60% of the initial moisture in the sawdust. The amount of drying that occurred was dependant on the throughput rate of sawdust. The overall energy efficiency of the system was approximately 60%. / Master of Science

no abstract provided by author / M.S.

The primary objective of this study was to improve residue chip quality at high production southern pine Sawmills. A general economic analysis suggested that improving sawmill residue chip quality could be beneficial to both pulp and sawmills. Studies were conducted at several sawmills to determine methods of improving residue chip quality. The first study examined the composition of material entering a residue chipper. Trim ends and oversize chips contributed the most pieces, but only 10% of the residue weight. Two-foot trim blocks accounted for the remaining material, 90% by weight. A number of these pieces resulted from slashing entire boards or cutting longer trim lengths into 2-foot pieces to clear them from the mill. Two studies were conducted to examine the possibility of leaving trim in longer lengths to improve piece orientation and stability. Both studies found significant improvements in chip quality, the over-thick chips decreased while the percentage of acceptable chips increased. Chip quality improved with each incremental increase in trim length, but increasing trim length to four feet alone accounted for 50% of the overall improvements. Four-foot trim lengths would generate an additional 4-5 tons of acceptable chips per day for the sawmill. Feed conveyor loading was found to affect chip quality. Highest chip quality was achieved when the feed conveyor was half-full, with two or three pieces entering simultaneously. An overloaded conveyor produced higher percentages of large chips, whereas chipping single pieces increased the percentage of smaller chips. The effect of seasonal temperatures on pin chip and fine production at southern pine and hardwood chip mills was examined as a secondary objective. The pin chip and fine content at the hardwood mills increased as temperatures decreased, but variability in species and inventory obscured the relationship. Southern pine chip mills experienced 4-5% increases in the pin chip and fine content during the winter months. Pin chips and fines increased 1% for every 10°F drop in temperature. / Master of Science

The objectives of this research were to modify and test a prototype sawdust dryer designed by Arrowhead Forest Products and a sawdust-fueled suspension burner developed at Virginia Tech. The dryer was designed to process green sawdust at small to medium-sized sawmills and pallet mills. The sawdust burner was designed to be the heat source for the dryer and serve more general needs. A series of trials were conducted to develop the operating parameters of the dryer and measure the dryer's effectiveness at reducing moisture content to 0%. Separate tests were conducted on the burner to determine maximum heat outputs and combustor efficiencies using sawdust fuel of various moisture contents and particle sizes. The sawdust dryer proved capable of reducing the moisture content to 0% after several passes through the system. The sawdust burner produced close to 400,000 BTU's/HR at calculated efficiencies over 90% and proved relatively insensitive to ranges of fuel moisture contents and particle sizes. / Master of Science

Thesis (M.S.)--Mississippi State University. Department of Forest Products. / Title from title screen. Includes bibliographical references.

O interesse por novas fontes renováveis de energia e, alem de uma tendência, uma necessidade da sociedade atual. Neste contexto, o uso da biomassa para fins energéticos apresenta-se de forma promissora, pois reúne atributos suficientes para contribuir com a diversificação da matriz energética local/nacional. No campo das possibilidades advindas da biomassa, se apresentam os resíduos de madeira de origem urbana, que poderiam contribuir, por exemplo, para aliviar a pressão sobre as florestas. Contudo, o uso destes resíduos na forma em que se encontram pode ser dificultado devido, entre outros, a presença de contaminantes e a alta heterogeneidade destes materiais. Neste sentido, o objetivo geral deste trabalho foi levantar os principais contaminantes presentes em resíduos de madeira de origem urbana, bem como realizar a caracterização energética desta madeira. O material analisado foi coletado em uma usina de reciclagem instalada no município de Piracicaba- SP. Os métodos e as analises descritos foram baseados em normas brasileiras, internacionais e em referencias da literatura. Os resultados são apresentados nos capítulos dois, três, quatro e cinco deste trabalho. / Interest in new renewable sources of energy is, beyond a global trend, a necessity of modern society. In this context, the use of biomass for energy purposes is presented as promising, as it gathers enough attributes to contribute to diversification of the local / national energy matrix. In the list of possibilities arising from biomass, present wood residues of urban origin, which could contribute, for example, to ease the pressure on forests. However, the use of this waste in the form in which they were discarded by society, without any prior treatment can be difficult, especially due to the presence of contaminants and also due to the high heterogeneity of these wastes. In this sense, the aim of this study was to identify the main contaminants in wood waste from urban as well as perform energy characterization of the material. The waste analyzed were collected in a recycling plant in the city of Piracicaba, SP. The methods used and the analyzes were based on Brazilian standards, international and literature references. The results are presented in the chapters two, three, four, five of this work.

São vários os fatores que contribuem para o aumento dos resíduos de madeira no Brasil. Dentre eles, a exploração predatória dos recursos naturais, as técnicas rudimentares de desdobro da madeira, como também, a falta de uma política de gerenciamento em empresas que processam madeira em relação aos resíduos e seu destino final. Contudo, a crescente demanda industrial por recursos florestais pode ser de grande valia na construção civil e em indústrias moveleiras, se levados em consideração a otimização do uso dos resíduos do processamento da madeira para o desenvolvimento de produtos alternativos e com valor agregado. Dessa forma, diante do uso de Inovação Tecnológica e a viabilidade técnica constatada em pesquisas recentes para o reaproveitamento desses resíduos na forma de Painel de Partículas Homogêneas, PPH, este trabalho utilizou resíduos de Pinus sp. e Eucalyptus sp. tratados com CCB, para fabricação de Painéis usados na construção de um Protótipo Arquitetônico, em escala real, com o intuito de unir várias pesquisas num só espaço e confirmar os resultados dos trabalhos em que este se baseia visando avaliar a eficiência da aplicabilidade desses painéis como revestimento de pisos e paredes. Os Painéis foram fabricados, em escala de laboratório, a partir de resíduos de madeira provenientes de áreas de reflorestamento na região de São Carlos, SP, e obtidos em serrarias, marcenarias e indústrias locais. A avaliação de seu desempenho ocorreu de acordo com a norma brasileira ABNT NBR 14810:2006 e normas internacionais (EUA e Canadá). A análise dos resultados e desempenho do Protótipo construído evidenciou a viabilidade e a eficiência do emprego destes painéis, possibilitando sua proposição ao mercado de revestimentos. / There are several factors that contribute to the increase of wood waste in Brazil. Among them, the predatory exploitation of natural resources, the rudimentary techniques of wood processing, but also the absence of wood waste management policies. However, the increase of industrial demand for forest resources may be important for construction and furniture industries if considered the optimization of wastes from wood processing, for the development of alternative value-added products. Through the use of technological innovation and the technical feasibility found in researches to recycle these wastes in the form of homogeneous particleboard, HP, this study used Eucalyptus sp. and Pinus sp. wastes treated with Copper Chromium and Boron (CCB), for manufacturing panels used in the construction of an full-scale architectural prototype, that empirically test the efficiency of the applicability of these panels as floor coverings and walls. The panels were manufactured in laboratory using wood waste from reforestation areas in the region of São Carlos, São Paulo State, obtained from sawmills, joinery and local industries according to the Brazilian Standard ABNT NBR 14810:2006 and the international standard (USA and Canada). By monitoring the results and the excellent performance of the prototype built the work proved the feasibility and efficiency of the use of these panels in the coatings market.