Thesis (Ph. D.)--Carnegie Mellon University, 2007. / Adviser: Keith, David W. Includes bibliographical references.

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Hydrogen as a clean energy carrier has drawn great attention. Production of H2 from sustainable bio-oil is considered an alternative for conventional fossil fuel based energy system, since the overall process of bio-oil converting to H2 ideally is carbon-neutral and hence environmental friendly. This study focuses on developing an adequate catalyst for bio-oil steam reforming to produce H2. Ruthenium and/ or nickel based catalysts supported on alumina, ceria-alumina or ceria-silica were synthesized by sol-gel method or incipient wetness impregnation and characterized using BET Surface area analysis, Powder X-Ray diffraction (XRD), Temperature Programmed Reduction (TPR) and Scanning Electron Microscopy (SEM). Steam reforming of selected model compounds, n-propanol, glycerol and acetic acid, was investigated in a fixed bed tubular flow reactor over the prepared catalysts at 450 or 500 °C. The effects of support nature, preparation method, catalyst composition and reaction temperature on the steam reforming activity and stability of catalysts were studied. Catalysts showing better performance in terms of reactant conversion and H2 yield were selected for investigating the steam reforming of an acetic acid/glycerol aqueous mixture, consisting of acetic acid and glycerol with a weight ratio of 3/7 similar to a bio-oil generated from fast pyrolysis of cellulose. The steam-to-carbon ratio (S/C) and the flow rate of feed were constant at 4 and 0.1 ml/min, respectively. The effluent gas was monitored by GC/TCD and the evolution of carbon conversion and product gas distribution as a function of time was studied. Among all catalysts investigated, the one with nominal composition A10C10N1Rnc showed the best performance in steam reforming at 500 °C as indicated by higher and more stable H2 yields achieved regardless the reactant used. In order to investigate the sorption-enhanced steam reforming, three CaO-based CO2 absorbents were synthesized: two derived from calcium acetate with or without MgO support, noted as CAM and CA, respectively, and the other MgO-supported one derived from calcium d-gluconate, denoted as CGM. Results from the 15-carbonation/regeneration-cycle test suggested that the MgO-containing absorbent CAM has the highest CaO molar conversion and stable CO2 absorption capacity. Though significantly higher CO2 absorption capacity was shown from absorbent CA in the first one cycle, CA absorbent soon lost most of the CO2 absorption capacity due to severe sintering. In addition, the CO2 absorption capacity of absorbent CGM might be underestimated due to insufficient carbonation time. The A10C10N1Rnc catalyst and the CAM absorbent were applied in the steam reforming of acetic acid/glycerol mixture at 500°C. However, no significant improvement can be observed in the presence of absorbent CAM

This work is dealing with the utilization of biomass feed stocks and wooden residue for gasification process to produce syn-gas suitable for the implementation of power plants for electricity generation and problem of gas production suitable for further chemical and energy purpose discussing the suitable practical purification methods, given that the complexity of theme and project which carried out through detailed analysis. Since the obtained gas has many types of unwanted contaminants. It was necessary to derive an effective cleaning method for gas purification from chemical contaminants especially tars components. The discussion of the definitions and methods for the determination of gas unwanted components and their removal technologies on the basis of the knowledge of data, collecting and analysis carried out through an experimental massive approach. The theoretical analysis of the gasification process for an effective tar reduction in the produced gas has been studied as well. Since the quality requirements for internal combustion engines, gas turbines and fuel cells using the primary measurement methods cannot be achieved for gas production, this work aimed removing different particulates and tar. The main emphasis is placed on the methods of high cleaning taking in account the chemical and thermal specifications of the gas which is based on the utilization of three different kinds of carbon materials successfully and efficiently char coal, black coke and active carbon for tar removal which has a major impact on the process parameters. The analysis was responding with the mechanism and the techniques of minimizing the resultant allowable concentration by using a suitable materials and verifying the operation conditions without affecting the gas thermal efficiency. The highlights of the theoretical and experimental work has been drawn up by a high concept cleaning allowing the production of a pure gas having a quality that meets the modern technical requirements for electricity generation. Functionality the most efficient cleaning methods were based in the current project for tar reduction on the quantity of tar removed, the materials used for tar cracking and the conditions of the experimental work as well. For a successful application, some proposals have been settled for industrial applications of gas cleaning.

Frente às mudanças climáticas, foi estabelecido via Acordo de Paris o compromisso do Brasil em reduzir as emissões de gases do efeito estufa em 37% até 2025 e 43% até 2030. A restauração de 12 milhões de hectares de florestas, dado o potencial das florestas em sequestrar carbono, é apresentada como uma das formas para atingir essas metas. Assim, entender o real potencial das florestas plantadas em sequestrar carbono, obtido via quantificação da biomassa, torna-se de grande importância e oportunidade. O objetivo do trabalho foi desenvolver modelos de predição de biomassa do estrato arbóreo para uma área restaurada com 12 anos de idade e avaliar a alocação de biomassa e carbono na vegetação arbórea em relação ao manejo silvicultural, arranjo de espécies e espaçamento de plantio nessa mesma área, localizada na Estação Experimental de Ciências Florestais de Anhembi, pertencente à ESALQ/USP. Para desenvolvimento das equações foi realizado o abate de 100 indivíduos arbóreos das 20 espécies presentes na área, escolhidos segundo uma amostragem estratificada em cinco classes de diâmetro por espécie. Em todas as árvores foi realizada cubagem rigorosa do tronco e galhos grossos e tiradas medidas de DAP, Altura total e Altura do tronco. Em seguida, foram divididas em quatro compartimentos: raízes, tronco, galhos grossos e copa, composta por galhos finos e folhas, e pesadaos separadamente. De cada compartimento foram obtidas amostras para determinação do teor de umidade e densidade básica dos discos, retirados em três posições do tronco: base, meio e topo e um na parte dos galhos grossos. Foram desenvolvidas quatro equações para predição de biomassa: Biomassa total acima do solo (Btas), Biomassa de tronco (Btr), Biomassa de copa (Bcp) e Biomassa de raiz (Brz). Para ajuste dos modelos foram testadas duas equações lineares, comumente utilizadas no meio florestal para cálculo de volume, e variações dessas equações com a inclusão de cinco variáveis preditoras: DAP, Altura, Altura do tronco, Comprimento de Copa e Densidade básica da madeira do tronco. As melhores equações obtidas incluíram pelo menos o DAP e densidade básica da madeira, sendo esta essencial para melhoria nos critérios de seleção de modelos. A aplicação das equações aos dados do inventário realizado em 2016 na área levou a estimativas de fixação de biomassa e carbono do estrato arbóreo bem variáveis entre os tratamentos, indo de 27,7 a 157,7 Mg.ha-1 para biomassa e de 13,0 a 74,1 Mg.C.ha-1 para carbono. As melhores parcelas apresentaram valores próximos aos encontrados em outros estudos em áreas de reflorestamento, mas abaixo do encontrado em florestas maduras. / In response to climate change, Brazil\'s commitment to reduce greenhouse gas emissions by 37% by 2025 and 43% by 2030 was established through the Paris Agreement. The restoration of 12 million hectares of forests, given the potential of forests in sequestering carbon, is presented as one of the ways to achieve these goals. Thus, understanding the real potential of planted forests to sequester carbon, obtained through the quantification of biomass, becomes of great importance and opportunity. The objective of this work was to develop biomass prediction models of the arboreal stratum for a restored area of 12 years old and to evaluate the biomass and carbon allocation in tree vegetation in relation to silvicultural management, species arrangement and planting spacing. The study area is part of an experimental study titled \"Models for the Recovery of Atlantic Forest Degraded Areas\", located at the Experimental Station of Forestry Sciences of Anhembi, belonging to ESALQ / USP. For the development of the equations, 100 individuals of the 20 species present in the area were felled according to a stratified sampling in five diameter classes per species. In all the trees was carried out rigorous volume measurements of the trunk and thick branches and taken dimensions of DBH, Total Height and Trunk Heignt. They were divided into four compartments: roots, trunk, thick branches and canopy, composed of thin branches and leaves, and weighed separately. From each compartment were taken samples to determine the moisture content and basic density of the discs, taken in three positions of the trunk: base, middle and top and one in the part of the thick branches. Four biomass prediction equations were developed: Total Biomass Above the Soil (Btas), Trunk Biomass (Btr), Canopy Biomass (Bcp) and Root Biomass (Brz). Two linear equations commonly used to calculate tree volume and its variations with the inclusion of five predictive variables: DBH, Height, Trunk Height, Cup Length and Basic Density of the trunk wood were used to develop the equations. The best equations obtained included at least the DBH and basic wood density, which is essential for improvement in the model selection criteria. The application of the equations in the inventory carried out in 2016 in the area led to estimates of biomass and carbon values of the tree stratum very variable between the treatments, ranging from 27.7 to 157.7 Mg.ha-1 for biomass and 13.0 to 74.1 Mg.C.ha-1 for carbon. The best plots presented values close to those found in other studies in reforestation areas, but lower than those found in mature forests.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-21T11:00:40Z No. of bitstreams: 2 Dissertação - William Rodrigues Martins - 2016.pdf: 595784 bytes, checksum: 3a2ef59ef753e50f8bafcc9b780fa57f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-21T11:01:10Z (GMT) No. of bitstreams: 2 Dissertação - William Rodrigues Martins - 2016.pdf: 595784 bytes, checksum: 3a2ef59ef753e50f8bafcc9b780fa57f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-21T11:01:10Z (GMT). No. of bitstreams: 2 Dissertação - William Rodrigues Martins - 2016.pdf: 595784 bytes, checksum: 3a2ef59ef753e50f8bafcc9b780fa57f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-01 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The objective of this work was to verify the volumetric production per area, the growth in height and diameter at breast height (DBH) in hybrid of Eucalyptus urophylla x E. grandis W. Hill., in reduced different planting spacings in southwest Goiás. The work was implemented in the Experimental Farm of the Federal University of Goiás, Regional Jataí (UFG / REJ), town of Jataí-GO, following the assumptions of completely randomized design, with three hybrids, two treatments for hybrid treatments and three replications, totaling 18 plots with 50 seedlings per plot. The hybrids were AEC1528, I144 and GG100 and the evaluated spacings were 3.0 m x 0.5 m and 3.0 m x 1.0 m. At 33 months of age tree were collected for the volume analysis, growth in height and diameter. The spacing of 3.0 m x 0.5 m in energy forests, affect the individual growth for both diameter and height, as to volume. The differentiation of hybrids was in height and production, where I144 hybrid gained greater prominence. The greatest expression in volume production, for wood with bark, not bark and bark volume was observed for 3.0 m x 0.5 m spacing. / Objetivou-se com este trabalho verificar a produção volumétrica por unidade de área, o crescimento em altura e diâmetro a altura do peito (DAP) em povoamentos de híbridos de Eucalyptus urophylla x E. grandis W. Hill., em diferentes espaçamentos reduzidos de plantio no sudoeste goiano. O trabalho foi implantado na Fazenda Experimental da Universidade Federal de Goiás, Regional Jataí (UFG/REJ), Município de Jataí-GO, seguindo os pressupostos do delineamento inteiramente casualizado, com seis tratamentos, e três repetições, totalizando 18 parcelas, com plantio de 50 mudas por parcela. Os híbridos avaliados foram o AEC1528, I144 e GG100 e os espaçamentos avaliados foram 3,0 m x 0,5 m e 3,0 m x 1,0 m. Assim observou-se aos 33 meses de idade que os crescimentos em diâmetro e altura são diretamente afetados pelo adensamento das plantas, e consequentemente com a redução da área útil disponível para cada planta. Os espaçamentos de 3,0 m x 0,5 em florestas energéticas afetam o incremento individual, tanto para diâmetro e altura, quanto para volume. A diferenciação dos híbridos ocorreu para o incremento em altura e produção, onde o híbrido I144 destacou-se. A maior expressão na produção volumétrica, para a madeira com casca, sem casca e o volume de casca foi observada para o espaçamento 3,0 m x 0,5 m.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 51-56). Also available on the World Wide Web.

第23回名古屋大学年代測定総合研究センターシンポジウム平成22(2010)年度報告