The co-firing technology of coal with biomass has been implemented to enhance the usage of biomass in power generation, thus reducing the release of greenhouse gas emissions. This study deals with the fireside issues, namely ash-related issues that arise during co-combustion of coal and biomass takes place. Ash release from biomass can lead to ash deposition problems such as fouling and slagging on surfacesof power generation boilers. The scope of this work includes the development of a conceptual model that predicts the ash release behaviour and chemical composition of inorganics in coal and biomass when combusted. An advanced analytical method was developed and introduced in this work to determine the speciation of biomass.The method known as pH extraction analysis was used to determine the inorganic speciation in three biomass samples, namely wood chips, wood bark and straw. The speciation of biomass and coal was used as an input to the model to predict the behaviour and release of ash. It was found that the main gas phases during the combustion of biomass are KCl, NaCl, K2SO4 and Na2SO4. Gas-to-particle formation calculations were carried out to determine the chemical composition of coal andbiomass when cooling takes place in the boiler. The results obtained in this work can be used in future work to determine the ash deposition of coal and biomass in boilers.

This thesis improves the understanding of the fate and transport of aerosols in North America. Aerosols play an important role climate modification, visibility, human health, and regulatory compliance. Through multiple aircraft-based and ground-based field campaigns, in situ ambient bulk aerosol concentrations will be determined across geographically diverse regions of the United States. By examining aerosol composition - specifically, inorganic ions and water-soluble organic carbon - as they are transported across the Pacific Ocean, we can observe background concentrations that may contribute to aerosol loading observed in many US communities. Furthermore, the aerosol continues to be modified by anthropogenic and biogenic emissions, dry and wet deposition, and secondary formation and transformation as it is transported across the continent. To capture some of these dynamic changes, aerosol will be extensively measured near the east coast of the US and Canada, and results may show significant anthopogenic, biogenic, and secondary transformation. Many results from the Northeastern United States and Southeastern Canada will be presented, and a special case study discussing acid-catalyzed formation of secondary organic aerosol in the region of northern Georgia, US is discussed. Lastly, through laboratory- and field-based instrument development, a commonly-deployed instrument is modified for improved measurement of organic carbon and results are presented herein.

La pyrolyse rapide de biomasse est un procédé de conversion thermochimique qui permet de produire principalement des huiles de pyrolyse valorisables dans le domaine de l’énergie. Les espèces inorganiques initialement présentes dans la biomasse sont à l’origine de problèmes d’instabilité des huiles, de dépôts et d’encrassement. L’objectif de ce travail consiste à mieux comprendre les mécanismes de transfert des inorganiques depuis la biomasse vers les huiles dans les procédés de pyrolyse rapide.Une méthodologie est mise au point afin de quantifier la répartition des alcalins et alcalino-terreux (K, Ca, Mg et Na), identifiés comme les plus néfastes, dans les produits (charbons et huiles) issus de pyrolyse de bois et de paille de blé. Deux dispositifs complémentaires sont utilisés, pour lesquels les bilans de matière bouclent de façon très satisfaisante: un réacteur pilote de pyrolyse rapide en lit fluidisé et un réacteur laboratoire en four tubulaire. Dans tous les cas, le charbon séquestre 99% des éléments minéraux issus de la biomasse. En outre, grâce à un dispositif original de condensation fractionnée des huiles, on démontre que plus de 60% des inorganiques restants dans les huiles de pyrolyse proviennent des aérosols, ce résultat ouvrant une discussion quant à leur origine. Les teneurs en inorganiques des huiles sont par ailleurs fortement liées à la présence de fines particules de charbon mal séparées dans le procédé. Les possibilités de traitement amont ou aval sont discutées, afin de diminuer ces concentrations.Enfin, des expériences parallèles associées à un modèle permettent de décrire quantitativement les mécanismes de transfert entre les particules de charbon et une phase liquide lors du stockage d’huiles de pyrolyse. / Biomass fast pyrolysis is a promising process for the preparation of bio-oils dedicated to energy production. Inorganic species originally present in biomass are known to induce problems such as bio-oil instability, deposits and fouling. The purpose of the present work is to better understand the mechanisms of inorganic species transfer from biomass to bio-oils in fast pyrolysis processes. A methodology is developed for quantifying alkali and alkali-earth species (K, Ca, Mg, Na) distribution in the products (chars and bio-oils) issued from wheat straw and beech wood fast pyrolysis. Two complementary devices are used: a pilot plant fluidized bed reactor, and a horizontal tubular reactor. Mass balances closures are accurately achieved. 99 wt.% of the inorganic species originally contained in biomass are recovered in the chars. Thanks to an original bio-oils fractional condensation device, it is shown that more than 60 wt.% of the inorganic content of overall bio-oil is contained in the aerosols. Different assumptions of possible origins of the aerosols are discussed. Inorganic content of bio-oil is strongly connected to the presence of fine chars particles which are not efficiently separated by the cyclones, and, hence recovered in the bio-oils. The possibilities of upstream or downstream treatments are discussed in order to lower inorganic content of bio-oils. Finally, the mechanisms of inorganics transfers between char particles and a liquid phase, during bio-oil storage, are quantitatively described on the basis of side experiments associated to a model.

As esculturas de cera do Museu Alpino, no Brasil, compostas por diversos materiais orgânicos e inorgânicos, apresentaram um tipo de degradação da superfície a qual foi investigada cientificamente através de metodologia diversificada baseada no uso de técnicas complementares, com cruzamento dos resultados. As matérias primas assim como os produtos de degradação foram caracterizadas físico-química e analiticamente. Foram empregadas as técnicas: análise térmica (termogravimetria, termogravimetria derivada e calorimetria exploratória diferencial); espectroscopia no infravermelho; análise elementar e microscopia eletrônica de varredura com analisador de dispersão de energia de raios X. A MEV/EDS foi utilizada para inspeção da micro morfologia da superfície e através dela foi possível identificar a presença de microorganismos que estavam causando a degradação físico-química pela forma como se fixaram na superfície através de suas hifas e por utilizarem os ácidos graxos presentes na cera como substrato metabólico. Os resultados de FTIR constataram a diminuição de ácidos graxos na superfície deteriorada em relação à superfície em bom estado. A TG/DTG e DSC permitiram avaliar o comportamento térmico das matérias primas e das amostras retiradas das obras de arte. Foi constatada a teoria da obra de arte como parte do ecossistema e a importância da utilização de políticas de preservação dos bens culturais por meio de ambientes controlados. / The waxy sculptures from Museum Alpino in Brazil, made of different organics and inorganics materials, presented a kind of surface degradation, which was scientifically investigated by multi-step methodology based on the use of complementary techniques with the interconnection of results. The raw materials as well as the degradation products were characterized physical-chemical and analytically. It was applied the following techniques: thermal analysis (thermogravimery, derivated thermogravimetry and differential scanning calorimetry); infrared spectroscopy; elemental analysis and scanning electronic microscopy with X ray energy dispersion system. The scanning electronic microscopy was used for the inspection of the micro morphology of the surface and after that it was possible to identify the presence of microorganisms which were causing the physical-chemical degradation analyzing the way they fixed their hyphae on the surface and the use of fat acids as metabolic substrate. Observing the FTIR results it was possible to notice the reduction of the fat acids on the deteriorated surface compared to the good surface. TG/DTG e DSC allowed to known the thermal behavior of the raw materials and the art works samples. It was possible to realize the theory of the work of art as part of the ecosystem and the importance of the cultural property\'s preservation policy by controlled ambient.

As esculturas de cera do Museu Alpino, no Brasil, compostas por diversos materiais orgânicos e inorgânicos, apresentaram um tipo de degradação da superfície a qual foi investigada cientificamente através de metodologia diversificada baseada no uso de técnicas complementares, com cruzamento dos resultados. As matérias primas assim como os produtos de degradação foram caracterizadas físico-química e analiticamente. Foram empregadas as técnicas: análise térmica (termogravimetria, termogravimetria derivada e calorimetria exploratória diferencial); espectroscopia no infravermelho; análise elementar e microscopia eletrônica de varredura com analisador de dispersão de energia de raios X. A MEV/EDS foi utilizada para inspeção da micro morfologia da superfície e através dela foi possível identificar a presença de microorganismos que estavam causando a degradação físico-química pela forma como se fixaram na superfície através de suas hifas e por utilizarem os ácidos graxos presentes na cera como substrato metabólico. Os resultados de FTIR constataram a diminuição de ácidos graxos na superfície deteriorada em relação à superfície em bom estado. A TG/DTG e DSC permitiram avaliar o comportamento térmico das matérias primas e das amostras retiradas das obras de arte. Foi constatada a teoria da obra de arte como parte do ecossistema e a importância da utilização de políticas de preservação dos bens culturais por meio de ambientes controlados. / The waxy sculptures from Museum Alpino in Brazil, made of different organics and inorganics materials, presented a kind of surface degradation, which was scientifically investigated by multi-step methodology based on the use of complementary techniques with the interconnection of results. The raw materials as well as the degradation products were characterized physical-chemical and analytically. It was applied the following techniques: thermal analysis (thermogravimery, derivated thermogravimetry and differential scanning calorimetry); infrared spectroscopy; elemental analysis and scanning electronic microscopy with X ray energy dispersion system. The scanning electronic microscopy was used for the inspection of the micro morphology of the surface and after that it was possible to identify the presence of microorganisms which were causing the physical-chemical degradation analyzing the way they fixed their hyphae on the surface and the use of fat acids as metabolic substrate. Observing the FTIR results it was possible to notice the reduction of the fat acids on the deteriorated surface compared to the good surface. TG/DTG e DSC allowed to known the thermal behavior of the raw materials and the art works samples. It was possible to realize the theory of the work of art as part of the ecosystem and the importance of the cultural property\'s preservation policy by controlled ambient.

La pyrolyse primaire rapide de cellulose, lignine, xylane et bois de bouleau (réel, reconstitué, lavé ou non) imprégnés par différents types de catalyseurs (KCl, MgCl2, NiCl2 et ZnCl2) est étudiée expérimentalement dans un four à image. De manière générale, l’effet résultant de l’ajout d’un catalyseur diffère selon le type de biopolymère. Il entraine cependant toujours la diminution de la vitesse de production des liquides et l’augmentation de celle des charbons (effets plus ou moins accentués selon la nature du catalyseur). La composition de phase gazeuse est également modifiée avec augmentation de la fraction volumique en H2. La nature et la morphologie des charbons dépendent également du type de catalyseur. Pour la cellulose, on montre que la quantité et la composition du composé intermédiaire liquide produit lors de la pyrolyse sont également modifiées. Des lois linéaires de comportement pyrolytique établies à partir de la simple superposition des observations faites avec les biopolymères pris isolément n’ont pu être établies avec précision, ce qui implique une phrase de modélisation. Le modèle repose sur l’écriture de bilans de matière et d’énergie au niveau des pastilles de biomasses soumises à une densité de flux de chaleur imposée. L’accord avec les résultats expérimentaux est satisfaisant mais souffre d’une mauvaise connaissance des propriétés physico-chimiques des biomasses. Les écarts proviennent également de la non prise en compte des interactions entre les biopolymères au sein des biomasses réelles. Des actions de recherche dans ces domaines pourraient être recommandées / The fast primary pyrolysis of cellulose, lignin, xylan and birch wood (natural, reconstituted, washed or not) impregnated by different types of catalysts (KCl, MgCl2, NiCl2 and ZnCl2) is experimentally studied in an image furnace. The effect of a catalyst addition differs according to the type of biopolymer. However, the decrease of the liquids and the increase of the char production rates are always observed (the effects are more or less stressed according to the nature of the catalyst). The composition of the gaseous phase is also modified with an increase of the H2 volume fraction. The nature and morphology of chars depend on the type of catalyst. The quantity and composition of the intermediate liquid compound formed during the pyrolysis of cellulose are also modified. It’s difficult to establish linear laws describing the pyrolytic behavior of biomasses from the simple overlapping of the observations made with basic biopolymers, implying the need of a modelling study. The model is based on mass and energy balances written at the level of biomasses pellets subjected to a given heat flux density. The agreement with the experimental results is quite good but suffers from a bad knowledge of the physicochemical properties of the biomasses. It is anticipated that the model could give better results if the influence of the interactions between basic biopolymers within the natural biomasses could be estimated and taken into account. Some researches in these domains could be recommended