Pulverized samples of Utah bituminous, Beulah (North Dakota) low Na lignite, Beulah high Na lignite and Texas (San Miguel) lignite coals were burned at a rate of 2.5 kg/hr in a laboratory furnace under various (overall fuel lean) combustion conditions. Particle size distributions (PSD) and size segregated particle filter samples were taken at various positions within the convection section. Temperature and gas concentrations were measured throughout. The evolution of the submicron PSD within the convection section for the four coals was similar, although the location of the initial particle mode at the convection section inlet varied with coal type. While staged (.8/1.2) combustion of the Utah bituminous coal had a variable effect on the volume of submicron aerosol produced, staged combustion of two of the three lignites (Beulah low Na and Texas) caused a definite increase in the submicron aerosol volume. Vapor enhancement due to a localized reducing atmosphere, which would effect coals of higher ash volatility or higher inherent ash content, is thought to explain this behavior. Depressed combustion temperatures associated with the high moisture content of the Beulah high Na lignite are thought to offset the effects of staging. Increased combustion temperatures (through oxygen enrichment) caused staged volume increases for the Beulah high Na lignite. Combustion temperatures are a controlling factor even at more extreme staging conditions. Chemical analysis of the size segregated particle samples show the trace elements, As, Pb, Zn and the major elements, Na and K to be enriched in the submicron aerosol. Auger depth profiles show these small particles to be comprised of a core enriched in Fe, Si, Ca and Mg and surface layers enriched in Na and K. These results point to a mechanism of homogeneous nucleation of low vapor pressure species followed by successive layering of progressively more volatile species. Volatile species are enriched in the submicron aerosol due to the large surface areas provided. Modeling efforts show that while coagulation may be the dominant mechanism to describe the aerosol evolving within the convection section, it cannot be used solely to predict the PSD. Another mechanism, presumably surface area dependent growth (condensation) must be included.

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The purpose of this study is to investigate the torrefaction and pelletization behavior, hydrophobicity, storage behavior, ash analysis on three different biomasses: one (willow pellets) from wood products, one (oat pellets) from agricultural products and one (poultry litter) from the non-lignocellulosic biomass products during the processes. Four different torrefaction temperatures from 200°C-300°C, at 10-60 minute residence times, 0%-2.4% oxygen concentration, were considered. Of these, 285°C for willow pellets, 270°C for oat pellets and 275°C for poultry litter were found to be optimum for hydrophobicity. Studies of XRD and SEM of biomass ash at 800°C, 900°C and 1000°C were also carried out. The aforementioned results indicate that torrefaction is a feasible alternative to improve energy properties of ordinary biomass and prevent moisture re-absorption during storage.

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The purpose of this study was to provide both a detailed geochemical analysis of the lithologies that comprise the Glacier Peak volcanic terrain and to summarize the small amounts of past research which has been completed on this Cascade volcano. A broad and extensive literature search indicates this area was previously unstudied in modern petrochemical terms. This study is a detailed petrochemical description and analysis of the mineral phases and the textures present in the various units in the Glacier Peak area (tephra, lava, breccia, and tuff). A scanning electron microprobe study of the scoriaceous basaltic lapilli of the White Chuck cinder cone, indicates that the contemporaneous basaltic cone is comprised of two or more compositional groups. One group is higher in calcium and iron than the other group. These distinct groups, in the lapilli tephra, may imply that the recent cone was built by a multitude of eruptions which variedslightly in composition over time.Through microprobe techniques and computer point-counting methods, the petrochemistry of the Glacier Peak and Gamma Ridge lava flows and the modal distributions of minerals present were determined. The micropobe data was checked for stochiometry and plotted on triangular variation diagrams. Histograms show the distribution along plagioclase binary, solid-solution series (NaAlS13O8 - CaA1Si208). Standard triangular variation diagrams were used to show the composition of the pyroxenes present in the samples (othopyroxene or clinopyroxene). A bimodal distribution of both the pyroxene and the plagioclase exists.The data and observations made in this thesis study, (1) support the sequence of the Glacier Peak magmatic events (i.e., the late Miocene to Pliocene Gamma Ridge hypersthene-augite dacite flows, the Pleistocene Glacier Peak hypersthene dacite flows, and the recent, basaltic, White Chuck cinder cone tephra eruptions), and (2) suggests changing magmatic conditions which would result in the observed disequilibrium features common throughout the Glacier Peak volcanic series (i.e., resorbed and relict crystals, normal and reverse zoning features, cognate clotting and polymodal distribution of plagioclase compositions).Finally, from these observations made on the sequence of the magmatic events of the Glacier Peak series and the conclusions from the analyzed compositions of these volcanic rocks, which suggest changing magmatic conditions, a generalized magmatic model (introduced by Eichelberger, 1977) has been applied to the Glacier Peak series. This model involves injection of basaltic magma into a more silicic magma chamber and results in a hybridized magma. This would be the Glacier Peak magma and would result in the petrological characteristics which imply disequilibrium conditions.

Biomass is increasingly used as a feedstock in global energy production. This may present operational challenges in energy conversion processes which are related to the inorganic content of these biomasses. As a larger variety of biomass is used the need for a basic understanding of ash transformation reactions becomes increasingly important. This is not only to reduce operational problems but also to facilitate the use of ash as a nutrient source for new biomass production. Ash transformation reactions were examined in the present work using the Lewis acid-base concept. The model presented in Paper I was further extended and discussed, including the definition of tertiary ash transformation reactions as reaction steps where negatively charged molecular ions, Lewis bases, other than hydroxides are present in the reactants. The effect of such reactions for bonding of various metal ions, Lewis acids, were discussed. It was found that the formation of various phosphates through secondary and tertiary ash transformation reactions is important for the behaviour of biomass ash in combustion. The suggested model was supported by findings in Papers II-VIII. The experimental findings in Papers II-VIII were discussed in terms of ash transformation reactions. The fuel design choices made to investigate the effect of phosphorus in particular on ash transformation reactions were high-lighted. Addition of phosphoric acid to woody-type and agricultural biomasses showed that phosphate formation has a large influence on the speciation of Si, S, and Cl. Co-combustion of a problematic agricultural residue with other biomasses showed that the relation between phosphorus, alkali and alkaline earth metal content is important. Co-combustion of biosolids with wheat straw was shown to greatly improve the combustion properties of wheat straw. It was suggested that fuel analyses should be presented using molar concentration (mole/kg) in diagrams based on ash transformation reactions and elements forming Lewis acids or bases. This may facilitate the assessment of the combustion behaviour of a fuel. Some comments were made on fuel design and additives, specifically pointing out that phosphorus content should always be carefully considered in relation to alkali and alkaline earth metals in fuels and fuel blends.