京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23394号 / エネ博第421号 / 新制||エネ||80(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 河本 晴雄, 教授 髙野 俊幸, 准教授 奥村 英之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

As production of ethanol climbs, nonood feedstocks need to be utilized such as lignocellulosic biomass. The sugars present in bio-oil produced by fast pyrolysis can potentially be fermented by microbial organisms to produce cellulosic ethanol. This study shows the potential for microbial digestion of the aqueous fraction of bio-oil in an enrichment medium to consume glucose and produce ethanol. In addition to glucose, inhibitors such as furans and phenols are present in the bio-oil. A pure glucose enrichment medium of 20 g/L was used as a standard to compare with glucose and aqueous fraction mixtures for digestion. 30% by volume of aqueous fraction in media was the most that could be consumed and yielded 0.4 g of ethanol per g of glucose. Inhibitor removal tests by extraction, activated carbon, air stripping, and microbial means were also mildly successful. Ethanol could potentially be produced for $14 per gallon using these methods.

Production of liquid fuels is a high national priority to provide transporation fuels. Production of liquid biouels from biomass has been idenfied as a viable goal over the next decades. Fast pyrolysis is the rapid thermal degradation of lignocellulosic biomass in the absence of oxygen. Levoglucosan, which can be hydrolyzed and fermented into bio-ethanol, is produced during the pyrolysis process of the cellulose contained in biomass. Pure cellulose results in the production of levoglucosan of more than 50% by feedstock weight while woody biomass typically produces about 3% during pyrolysis. Researchers have performed significant research into methods to increase yields of levoglucosan and other associated anhydrosugars during pyrolysis. Most research has focused on mild acid pretreatment of biomass feedstocks prior to pyrolysis. Such treatment demineralizes and removes hemicellulose that appears to hinder the production of levoglucosan during pyrolysis. The objective of this study is to move beyond simple acid pretreatment to increase pyrolytic anhydrosugars yields during fast pyrolysis.

Biomass burning aerosols play an important role in the chemistry and physics of the atmosphere and therefore, affect global climate. Biomass burning aerosols are generally aqueous and have a strong saccharidic component due to the combustion and pyrolysis of cellulose, a major component of foliar fuel. This class of aerosol is known to affect both the absorption and scatter of solar radiation. Also, biomass burning aerosols contribute to cloud formation through their action as cloud-condensation nuclei. Many questions exist about the chemical speciation and chemical aging of biomass burning aerosols and how this affects their atmospheric properties and ultimately, global climate. Also, knowledge of the chemical components of these aerosols is important in the search for chemical tracers that can give information about the point or regional source, fuel type, and age of a biomass burning aerosol parcel. Levoglucosan was chosen for these studies as a model compound for biomass burning aerosols because of its high measured concentrations in aerosol samples. Levoglucosan often dominates the aerosol composition by mass. In this dissertation, laboratory proxy systems were developed to study the solution-phase chemistry of levoglucosan with common atmospheric reactants found in biomass burning aerosols (i.e. H+, •OH). To mimic these natural conditions, acid chemistry was studied using sulfuric acid in water (pH=4.5). The hydroxyl radical (•OH) was produced by the Fenton reaction which consists of iron, hydrogen peroxide and acid (H2SO4) in aqueous solvent. For studies in aqueous sulfuric acid, oligomers of levoglucosan were measured by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS). A rational mechanism is proposed based on both the acid-catalyzed cationic ring-opening of levoglucosan and nucleophilic attack of ROH from levoglucosan on the hemi-acetal carbon to produce pyranose oligomers through the formation of glycosidic bonds. Oligomer formation is further supported by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Reactions of levoglucosan with •OH produced from Fenton chemistry were studied in solution. Two modes of oligomerization (2000 u) were observed for reaction times between 1 and 7 days using MALDI-TOF-MS and laser desorption ionization (LDI) TOF-MS. Single-mass unit continuum mass distributions with dominant -2 u patterns were measured and superimposed by a +176/+162 u oligomer series. This latter oligomer pattern was attributed to a Criegee rearrangement (+14 u) of levoglucosan, initiated by •OH, forming a lactone (176 u). The acid-catalyzed reaction of any ROH from levoglucosan (+162 u) forms an ester through transesterification of the lactone functionality, whereupon propagation forms polyesters. Proposed products and chemical mechanisms are suggested as sources and precursors of humic-like substances (HULIS), which are known to possess a large saccharic component and are possibly formed from biomass burning aerosols. These products could also serve as secondary tracers, giving further information on the source and age of the aerosol.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第20097号 / エネ博第344号 / 新制||エネ||69(附属図書館) / 33213 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 坂 志朗, 教授 髙野 俊幸, 准教授 河本 晴雄 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM

Environmental applications of pyrogenic carbon, aka black carbon (BC), have been hampered due to the poor characterization and quantification of environmental BC. This dissertation was dedicated to the better characterization of environmental char/charcoal BC (char-BC), the most heterogeneous and the less identifiable group in the BC continuum. The analytical approach developed for char-BC was further incorporated with other BC methods in environmental samples for a comprehensive assessment of combustion-derived carbon inputs in different environmental systems. The present study firstly evaluated the feasibility of using levoglucosan, a marker derived from cellulose/hemocellulose combustion, to characterize and quantify char-BC in the environment. Levoglucosan was found exclusively in BC materials derived from biomass combustion albeit in highly variable yields across different char-BC. A further examination of synthetic chars showed that temperature is the most influential factor affecting levoglucosan yield in char. Notably, levoglucosan was only detectable in low temperature char samples (150-350 degrees C), regardless of plant species. These results demonstrated that levoglucosan could serve as a good qualitative indicator for the presence of char produced under low temperature conditions in soil, sediments, and aerosols. Results of lignin analysis on the synthetic chars further reveal that combustion can greatly decrease the yield of the eight major lignin phenols with no lignin phenols detected in any synthetic char produced at greater than or equal to 400 degrees C. The values of all lignin parameters show significant shifts with increasing combustion severity (temperature and/or duration), indicating that thermal alteration is an important abiotic lignin degradation process. Hence the input of char-BC in the environments represents a terrestrial organic matter source with highly altered lignin signatures. Finally, a multi-proxy approach, including elemental (soot-BC) and molecular (levoglucosan, polycyclic aromatic hydrocarbons (PAHs), and lignin oxidation products) proxies, was adopted to investigate the centennial-scale temporal distribution of combustion products in four sediment cores from Puget Sound basins, WA. The observed temporal trends of soot-BC and combustion PAHs fluxes reflect the evolution of energy consumption and the positive effects of environmental regulations. The distinct temporal patterns of soot and PAHs among cores demonstrate that urbanization is a crucial factor controlling the inputs of combustion byproducts to the environment. On the other hand, the trends of levoglucosan may be more relevant to the climate oscillation and thus show a regional distribution pattern. Our results demonstrate that environmental loading of combustion byproducts is a complex function of urbanization and land use, fuel usage, combustion technology, environmental policies, and climate changes.

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No. of bitstreams: 2 Dissertação - Isabela Milhomem Dias - 2018.pdf: 2608349 bytes, checksum: 1c79136e1c7ae84fabeaf8314b29fda9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-26 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Air pollution is an environmental problem present in many regions of the world. Aerosols or particulate matters (PM) are atmospheric pollutants associated with climate changes and human health, and prompt a great number of deaths each year. In Brazil, the forest fires and the burning of sugarcane are some of the sources of emissions of gases and PM into the atmosphere. The anhydrosugar levoglucosan and its stereoisomers, mannosan and galactosan, are biomass burning markers, because they are produced by cellulose pyrolysis at high temperatures. This work developed a method using Paper-based Analytical Devices (PADs) with colorimetric detection to determine biomass burning markers in samples of PM and rainwater of Goiânia city. In this method, the levoglucosan present in the samples was hydrolyzed to glucose, and after an enzymatic reaction, showed a magenta coloration using a chromogen agent. The PADs were scanned generate a digital image, and the color intensities were correlated with the analyte concentrations. The method showed a conversion rate of levoglucosan to glucose of 81%, good linearity in the range of 0 to 0.4 mmol.L-1 , a limit of detection (LD) of 2 μg.mL-1 and a limit of quantification (LOQ) of 6 μg.mL-1 for hydrolysis in sulfuric acid. Moreover, the method presented selectivity for these markers, because the interferents can be detected and quantified. The concentrations of levoglucosan determined in PM were high and varied from 0.08 to 1.10 μg.m-3 (0.44 ± 0.29; n = 10), these concentrations were similar to those obtained in the Amazon, which is a region exposed to extensive biomass burning due to deforestation. In rainwater samples, collected in two different events, levoglucosan was detected showing that biomass burning has a significant contribution in the emission of gases and PM in Goiânia atmosphere. The method developed in this work using PADs with colorimetric detection was successfully apllied to levoglucosan determination in PM and rainwater samples. This process used low volume of samples and reagents, the analysis are rapid, the operation is easy, the cost of production is low and the devices are portable, being an advantageous technique. / A poluição atmosférica é um problema ambiental vivenciado por diversas regiões do mundo. Os aerossóis ou material particulado (MP) são poluentes atmosféricos que estão associados a mudanças climáticas e a saúde humana, sendo responsável por um crescente número de mortes a cada ano. No Brasil, os incêndios florestais e a queima da cana-de-açúcar são algumas das fontes de emissões de gases e MP para a atmosfera. Os anidro açúcares levoglucosano e seus estereoisômeros manosano e galactosano, são marcadores de queima de biomassa, pois estes são produzidos por meio da pirólise celulósica em altas temperaturas. Assim, este trabalho buscou desenvolver um método empregando Paper-based Analytical Devices (PADs, Dispositivos Analíticos fabricados em Papel) com detecção colorimétrica para determinar marcadores de queima de biomassa em amostras ambientais: MP e água de chuva, da cidade de Goiânia. Neste método, o levoglucosano contido nas amostras foi hidrolisado à glicose e após reação enzimática apresentou coloração magenta na presença de cromógeno. O PAD foi escaneado gerando uma imagem digital cuja intensidade de cor foi correlacionada à concentração do analito. O método apresentou taxa de conversão de levoglucosano em glicose de 81%, boa linearidade na faixa de trabalho de 0 a 0,4 mmol.L-1 , limite de detecção (LD) de 2 μg.mL-1 e limite de quantificação (LQ) de 6 μg.mL-1 para hidrólise em ácido sulfúrico. Além disso, o método possui seletividade para estes marcadores, pois os interferentes podem ser detectados e quantificados. As concentrações de levoglucosano determinadas em MP foram altas e variaram de 0,08 a 1,10 μg.m-3 (média de 0,44 ± 0,29; n = 10), estas concentrações foram similares às determinadas na Amazônia, uma região que sofre com intensa queima de biomassa devido ao desmatamento. Nas amostras de água de chuva, coletadas em dois eventos diferentes, levoglucosano foi detectado, mostrando que a queima de biomassa tem significativa contribuição na emissão de gases e partículas para a atmosfera de Goiânia. O método desenvolvido neste trabalho empregando PAD com detecção colorimétrica apresenta potencialidade elevada para análise de levoglucosano em amostras de MP e água de chuva, possuindo como vantagens a utilização de volumes reduzidos de amostras e reagentes, análise rápida, fácil operação, baixo custo de produção e portabilidade.

Tropospheric fine particulate matter (PM) poses serious health risks and has a significant impact on global climate change. The measurement of various aspects of PM is challenging due to its complex chemical nature. This dissertation addresses various aspects of PM, including composition, measurement, and visibility. The U.S. Environmental Protection Agency (EPA) proposed a new secondary standard based on visibility in urban areas using 24-h averaged measurements of either light scatter or PM concentration. However shorter averaging times may better represent human perception of visibility. Data from two studies conducted in Lindon, UT, 2012, and Rubidoux, CA, 2003, were used to compare different techniques to estimate visibility, particularly the effect of relative humidity on visibility estimations. Particle composition was measured in Salt Lake City during January-February of 2009. One-hour averaged concentrations of several gas phase and particle phase inorganic species were measured. The results indicate ammonium nitrate averages 40% of the total PM2.5 mass in the absence of inversions and up to 69% during strong inversions. Also, the formation of ammonium nitrate is nitric acid limited, while the formation of ozone appears to be oxidant and volatile organic carbon (VOC) limited. Reduction of NOx will reduce ammonium nitrate secondary particle formation, however, a decrease in NOx may increase ozone concentration.Due to the complexity of PM it is poorly characterized. A large fraction of PM is composed of organic compounds, but these compounds are not regularly monitored due to limitations in current sampling techniques. The GC-MS Organic Aerosol Monitor (OAM) combines a collection device with thermal desorption, gas chromatography and mass spectrometry to quantitatively measure the carbonaceous components of PM on an hourly averaged basis. A compact GC and simple pre-concentrator were developed for the system to decouple separation from manual injection and enhance separation of environmentally-relevant polar organic compounds, such as levoglucosan. The GC-MS OAM is fully automated and has been successfully deployed in the field. It uses a chemically deactivated filter for collection followed by thermal desorption and GC-MS analysis. Laboratory tests show that detection limits range from 0.2 to 3 ng for many atmospherically relevant compounds. The GC-MS OAM was deployed in the field for semi-continuous measurement of the organic markers, levoglucosan, dehydroabietic acid, and several polycyclic aromatic hydrocarbons (PAHs) during winter (January to March), 2015 and 2016. Results illustrate the significance of this monitoring technique to more fully characterize the organic components of PM and identify sources of pollution.

No description available.

A composição química do material particulado fino (MP2,5) e MP10 foi determinado em três sítios representativos do estado de São Paulo: Cidade Universitária (SPA), Piracicaba (PRB) e São Luis do Paraitinga (MAT); e em duas outras cidades sul-americanas, Bogotá (BOG) e Buenos Aires (BAI). As coletas ocorreram nos anos de 2007, 2008 e 2009. Para caracterizar os sítios foram determinados íons inorgânicos, orgânicos e levoglucosano no MP coletado em filtros de fibra de quartzo. O material carbonáceo, sulfato, nitrato e amônio foram as espécies determinadas mais abundantes na massa do MP2,5 e MP10, sobretudo nas amostras dos sítios do estado de São Paulo. A contribuição destes componentes está associada à formação secundária das partículas atmosféricas nos centros urbanos. Entretanto, o cátion predominante das amostras nos sítios BOG e BAI foi o cálcio. Esta espécie no MP atmosférico, juntamente com o Mg2+, são atribuídos à ressuspensão de solo. Por meio dos estudos das trajetórias de massas de ar foi observada a influência de outras fontes sobre o material particulado local. A entrada de partículas provenientes de queima de madeira e biomassa em regiões urbanas foi associada à presença do levoglucosano, correlacionado com K+ e outros marcadores ambientais. O uso de ferramentas estatísticas, como as razões diagnósticas, as matrizes de correlações e análise de componente principal (ACP), contribuíram para a caracterização dos sítios estudados, distinguindo estatisticamente as emissões veiculares, das atividades agrícolas, industriais e queima da biomassa, entre outras. / The chemical composition of fine particulate matter (PM2.5) and PM10 was determined in three sites representative of the São Paulo State: University City (SPA), Piracicaba (PRB) and São Luis of the Paraitinga (MAT); and in two other South American cities, Bogotá (BOG) and Buenos Aires (BAI). The samples were collected in 2007, 2008 and 2009. In order to characterize the chemical composition of PM collected on quartz fiber filters, water-soluble ions and levoglucosan were determined. Carbonaceous material, sulfate, nitrate and ammonium were the most abundant species in the PM2.5 and PM10 samples, especially those from the São Paulo sites. The contribution of these components is associated with secondary formation of atmospheric particles in urban centers. However, calcium was the predominant cation of samples from BOG and BAI sites. PM atmospheric presence of Ca2+ and Mg2+ is attributed to soil dust. Through the studies air mass trajectories was observed the influence of other sources on the local particulate matter. The input of particles from burning wood and biomass in urban areas was associated with the presence of levoglucosan with K+ and other environmental tracers. The use of statistical tools such as diagnostic reasons, correlation matrices and principal component analysis (PCA), contributed to the characterization of sites studied. Therefore it was possible to distinguish statistically vehicle, agricultural activities, industrial and biomass burning emissions, among others.