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Impaired lung function in individuals chronically exposed to biomass combustion

Ferraz da Silva, Luiz Fernando; Dias Medici Saldiva, Silvia Regina; Nascimento Saldiva, Paulo Hilario; Dolhnikoff, Marisa
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE; SAN DIEGO Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE; SAN DIEGO
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.77%
Background: The use of biomass for cooking and heating is considered an important factor associated with respiratory diseases. However, few studies evaluate the amount of particulate matter less than 2.5 mu in diameter (PM2.5), symptoms and lung function in the same population. Objectives: To evaluate the respiratory effects of biomass combustion and compare the results with those of individuals from the same community in Brazil using liquefied petroleum gas (Gas). Methods: 1402 individuals in 260 residences were divided into three groups according to exposure (Gas, Indoor-Biomass, Outside-Biomass). Respiratory symptoms were assessed using questionnaires. Reflectance of paper filters was used to assess particulate matter exposure. In 48 residences the amount of PM2.5 was also quantified. Pulmonary function tests were performed in 120 individuals. Results: Reflectance index correlated directly with PM2.5 (r=0.92) and was used to estimate exposure (ePM2.5). There was a significant increase in ePM2.5 in Indoor-Biomass and Outside-Biomass, compared to Gas. There was a significantly increased odds ratio (OR) for cough, wheezing and dyspnea in adults exposed to Indoor-Biomass (OR=2.93, 2.33, 2.59, respectively) and Outside-Biomass (OR=1.78...

Cogeração de Eletricidade Utilizando Bambu no Brasil: Aspectos Técnicos Econômicos e Ambientais; Bamboo is a grass, woody perennial with good biomass productivity per hectare. Bamboo can be grown virtually anywhere in the Brazilian territory and almost all existing plantations are located in tropical and rainy areas, offering excellent conditions for the production and use of biomass energy in large scale. Two Brazilian companies already utilize bamboo biomass in large scale in Brazil. The Penha Group, in Bahia, burns bamboo in boilers and uses the steam in the process for recycling paper. Joao Santos Group uses bamboo as raw material in the manufacture of pulp and paper. However in any case there is the use of this biomass for energy cogeneration, which is the most efficient technology for energy conversion. Therefore, this thesis analyses the use of bamboo as fuel for electricity cogeneration in Brazil considering the technical aspects, as well as the corresponding economic and environmental system deployment. Also, to study the development of the productive chain of bamboo in large scale in Brazil, specifically targeted for energy purposes, this paper presents the survey of data concerning the different production systems adopted by companies, both in the cultivation and processing of biomass. Based in these results it is analyzed an efficient cogeneration system using bamboo as fuel on large scale. Obtained results show that the power to be produced in an efficient cogeneration system (60 bar, 490 oC), from 17 tones of bamboo per hour, is 3,5 MW but, with the existing bamboo production models, there is no economic feasibility, as discussed in the paper. Regarding environmental aspects, it must be noted that the bamboo is as perennial plant, able to produce biomass annually without replanting, and so appears to be an excellent carbon sink.

Guarnetti, Rodrigo Luiz
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 05/12/2013 PT
Relevância na Pesquisa
36.77%
O bambu e uma graminea lenhosa, renovavel, perene e com boa produtividade de biomassa por hectare. Pode ser cultivada praticamente em todo o territorio brasileiro, que esta quase todo localizado em regioes tropicais e chuvosas, oferecendo excelentes condicoes para a producao e o uso energetico da biomassa de bambu em larga escala. O setor de papel e celulose apresenta boas perspectivas na producao de papel de fibras longas utilizando bambu, no entanto, apenas duas empresas brasileiras utilizam esse tipo de biomassa em grande escala no Brasil: O Grupo Penha queima o bambu em caldeira e utiliza o vapor no processo de reciclagem de papel e O Grupo Joao Santos utiliza a biomassa como materia prima na fabricacao de papel e celulose. No entanto, em ambos os casos a biomassa nao e utilizada em sistema de cogeracao de eletricidade, considerada uma tecnologia eficiente de conversao. O objetivo dessa tese e estudar os aspetos tecnicos, economicos e ambientais da implantacao de um sistema de cogeracao de eletricidade utilizando biomassa de bambu. Sao estudadas as caracteristicas agronomicas e as particularidades da implantacao de cultivos comerciais de bambu voltado a fins energeticos. Visando determinar o Poder Calorifico (PCS) de cinco diferentes especies consideradas adaptadas ao clima brasileiro e conhecidas como boas produtoras de biomassa por hectare...

Above- and below-ground biomass and carbon dynamics in Brazilian Cerrado wet grasslands

Fidelis, Alessandra; Lyra, Maria Fernanda di Santi; Pivello, Vânia Regina
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 356-364
ENG
Relevância na Pesquisa
36.76%
Questions: Grasslands are usually neglected as potential carbon stocks, partially due to the lack of studies on biomass and carbon dynamics in tropical grasslands. What is the importance of Brazilian tropical wet grasslands as carbon sinks? Does fire frequency and season affect biomass and carbon allocation in Brazilian wet grasslands? Location: Wet grasslands, tropical savanna, Jalapão, Tocantins, northern Brazil. Methods: We determined biomass above- and below-ground, estimated carbon stocks in biennially burned plots (B2) and plots excluded from fire for 4 yr (B4). Moreover, we determined biomass in both rainy and dry seasons. Samples were 0.25 m × 0.25 m × 0.2 m (eight samples per treatment, applying a nested design, total of 48 samples). The biomass was classified in above-ground graminoids, forbs and dead matter, and below-ground roots and other below-ground organs. We used ANOVA to compare variables between treatments and seasons. Results: More than 40% of the total biomass and carbon stocks were located below-ground, mostly in roots. A high proportion of dead biomass (B4) was found in the above-ground material, probably due to low decomposition rates and consequent accumulation over the years. Although these grasslands do not experience water stress...

Biomassa de epífitas vasculares em floresta de restinga na Mata Atlântica; Biomass of vascular epiphytes in seasonally flooded coastal forest (restinga) in the Atlantic Forest

Yvonne Vanessa Bakker
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/02/2015 PT
Relevância na Pesquisa
36.79%
A Mata Atlântica é um dos principais biomas do mundo sendo considerada um dos 25 hotspots de biodiversidade. Dentre os ecossistemas associados à Mata Atlântica, a Floresta de Restinga foi quase totalmente dizimada, restando apenas 0,5% de sua área original. A Restinga se caracteriza por ocorrer nos cordões arenosos ao longo da costa onde o solo é distrófico e sujeito a inundações sazonais. Entre as comunidades que ocorrem nas florestas de restinga, destacam-se as epífitas vasculares que, por não terem contato com o solo, possuem adaptações ecológicas que garantem a aquisição de nutrientes via deposição seca e úmida. Para avaliar o papel das epífitas vasculares no funcionamento das Florestas de Restinga realizou-se o levantamento quantitativo da biomassa das epífitas vasculares em uma área de um hectare de Floresta de Restinga, no Núcleo Picinguaba do Parque Estadual da Serra do Mar (PESM), no litoral norte paulista, município de Ubatuba. Para tanto, foi coletado todo o material epifítico presente em 23 forófitos com DAP entre 4,9 e 41,7 cm, previamente selecionados. Cada forófito foi dividido por zonas ecológicas (copa, galhos e tronco), buscando amostrar os indivíduos arbóreos com diferentes (a) arquitetura de copa (A...

Development of computational methods for the determination of biomass composition and evaluation of its impact in genome-scale models predictions

Santos, Sophia Torres
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Dissertação de Mestrado
Publicado em //2013 ENG
Relevância na Pesquisa
36.79%
Dissertação de mestrado em Bioinformática; The use of genome-scale metabolic models is rapidly increasing in fields such as metabolic engineering. An important part of a metabolic model is the biomass equation, since this reaction will be used as the objective function in most simulation approaches. In order to obtain a reliable metabolic model, the biomass precursors and their coefficients must be as precise as possible. Ideally, the determination of the biomass composition would be performed experimentally, but due to technical limitations in cellular components quantification, budget restraints and time limitations, this is often established by approximation to closely related organisms. Computational methods however, can extract some information from the genome, such as amino acid and nucleotide compositions. One main objective in this study was to evaluate how biomass precursor coefficients computationally determined, affected the predictability of several genome-scale metabolic models by comparison with experimental data. Sensitivity analysis studies were performed with the Escherichia coli iAF1260 metabolic model concerning specific growth rate and flux distribution. Several metabolic models, whose biomass composition had been experimentally determined...

Biomass expansion factors for Eucalyptus globulus stands in Portugal

Soares, P.; Tomé, Margarida
Fonte: INIA Publicador: INIA
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
36.82%
One of several procedures for estimating carbon stocks in forests is the estimation of tree or stand biomass based on forest inventory data. The two approaches normally used to convert field measurements of trees to stand biomass values are allometric biomass equations and biomass expansion factors (BEFs). BEFs are used in published National Forest Inventory results in which biomass is not estimated or as a complement of growth models that do not include biomass predictions. In this paper, the effectiveness of BEFs for estimating total stand biomass in Portuguese Eucalyptus globulus plantations was analyzed. Here, BEF is defined as the ratio of total stand biomass (aboveground biomass plus root biomass) to stand volume with bark. To calculate total biomass, an equation was developed to estimate root biomass as a function of aboveground biomass. Changes of BEF with stand variables were analyzed. Strong relationships were observed between BEF and stand age, stand basal area, stand volume and dominant height. Consequently, an equation to predict BEF as a function of stand variables was fitted, and dominant height was selected as the predictor stand variable. Estimates of total stand biomass based on individual tree allometric equations were compared with estimates obtained with a constant BEF (0.77)...

Ionic liquids as a tool for lignocellulosic biomass fractionation

Lopes, André; João, Karen; Morais, Ana Rita; Bogel-Lukasik, Ewa; Bogel-Lukasik, R.
Fonte: Chemistry Central Ltd. Publicador: Chemistry Central Ltd.
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
36.79%
Lignocellulosic biomass composes a diversity of feedstock raw materials representing an abundant and renewable carbon source. In majority lignocellulose is constituted by carbohydrate macromolecules, namely cellulose and hemicellulose, and by lignin, a polyphenilpropanoid macromolecule. Between these biomacromolecules, there are several covalent and non-covalent interactions defining an intricate, complex and rigid structure of lignocellulose. The deconstruction of the lignocellulosic biomass makes these fractions susceptible for easier transformation to large number of commodities including energy, chemicals and material within the concept of biorefinery. Generally, the biomass pre-treatment depends on the final goal in the biomass processing. The recalcitrance of lignocellulose materials is the main limitation of its processing once the inherent costs are excessively high for the conventional pre-treatments. Furthermore, none of the currently known processes is highly selective and efficient for the satisfactory and versatile use, thus, new methodologies are still studied broadly. The ionic liquid technology on biomass processing is relatively recent and first studies were focused on the lignocellulosic biomass dissolution in different ionic liquids (ILs). The dissolution in IL drives to the structural changes in the regenerated biomass by reduction of cellulose crystallinity and lignin content contrasting to the original biomass. These findings provided ILs as tools to perform biomass pre-treatment and the advantageous use of their specific properties over the conventional pre-treatment processes. This review shows the critical outlook on the study of biomass dissolution and changes occurred in the biomass during this process as well as on the influence of several crucial parameters that govern the dissolution and further pre-treatment process. The review of currently known methods of biomass fractionation in IL and aqueous-IL mixtures is also discussed here and perspectives regarding these topics are given as well.

China - Biomass Cogeneration Development Project : Fuel Supply Handbook for Biomass-Fired Power Projects

World Bank
Fonte: World Bank Publicador: World Bank
Relevância na Pesquisa
36.89%
This handbook provides an overview of the main topics that need consideration when managing the supply of biomass to large biomass power plants. It will help investors in China to develop, with assistance of local biomass supply experts, their own solutions. The focus is on biomass residues, in particular agricultural residues (mainly straw and stalks) and forestry residues (mainly residues from forestry operations). This handbook covers a wide range of topics related to biomass fuel supply risk in the planning and preparation stages for a biomass-fired power plant. Chapter two introduces the use of biomass as an energy source, including fuel selection considerations and the fuel standards and specifications required to match a particular fuel supply to a power generation system. Chapter three describes the use of biomass resource assessments at the project planning stage. Chapters four and five give insight into the biomass supply from straw and forestry residues, respectively. Finally, fuel supply management is covered in chapter six...

Forests, Biomass Use and Poverty in Malawi

Bandyopadhyay, Sushenjit; Shyamsundar, Priya; Baccini, Alessandro
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Relevância na Pesquisa
36.76%
In this paper, the authors seek to answer three questions about poverty and forests in Malawi: (1) What is the extent of biomass available for meeting the energy needs of the poor in Malawi and how is this distributed? (2) To what extent does fuelwood scarcity affect the welfare of the poor? (3) How do households cope with scarcity? In particular, do households spend more time in fuelwood collection and less time in agriculture in response to scarcity? The authors attempt to answer these questions using household and remote-sensing data. They find that 80 percent of rural poor households in Malawi are likely to benefit from an increase in biomass per hectare in their community. Rural women respond to biomass scarcity by increasing the time they spend on fuelwood collection. But the actual decrease in consumption expenditure and increase in time in fuelwood collection are small and biomass scarcity is not associated with a reduction in agricultural labor supply.

Bolivia : National Biomass Program

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
Relevância na Pesquisa
36.83%
Over the past two decades, the Energy Sector Management Assistance Program (ESMAP) has financed several projects to assist Bolivia in the development of its energy sector, including the Bolivia Country Program First Phase, which contributed to the design of a national energy plan, the definition of policies and actions applicable to rural energy and energy efficiency, and a significant structural reform of the energy sector, and also supported the preparation of the Bolivia National Biomass Program (NBP) aimed at enhancing the efficient use of biomass as an energy source, while improving the quality of life of the rural population -- in consistence with the objectives of the World Bank Country Assistance Strategy (CAS) in Bolivia regarding accelerated growth and development of private sector activities. An agreement subscribed in November 1997 between the Government of the Netherlands and the World Bank assigned the execution of NBP to ESMAP, with the Vice Ministry of Energy and Hydrocarbons (VMEH) as its counterpart in Bolivia.

Microbial activity and biomass in saline soils as affected by carbon availability.

Elmajdoub, Bannur Mohamed Ahmed
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
36.81%
Soil salinity is a serious land degradation problem which reduces plant growth and microbial activity due to (1) low osmotic potential which causes plant water stress, and (2) ion toxicity and ion imbalances (nutrient deficiencies) as result of high salt concentrations in the soil solution. Therefore, salinity affects organic matter turnover by influencing the amount of organic matter input in the soil and decomposition rate. Microbial activity and biomass in saline soils have been extensively studied, but a little is known about the effect of organic carbon (OC) addition on adaptation of soil microbes to salinity. The objective of this thesis was to determine the effect of OC availability on adaptation of soil microbial activity and biomass to salinity. In most experiments described in this thesis, one non-saline and four saline soils from the field with similar texture (sandy clay loam) and electrical conductivities in a 1:5 soil: water extract (EC₁﹕₅) of 0.1, 1.1, 3.1 and 5.2 dS m⁻¹ or electrical conductivity of the saturation extract (ECₑ) of 1, 11, 24 and 43 dS m⁻¹ were used. In other experiments a non-saline loamy sand was amended with NaCl to achieve a range of EC levels. The optimum water content for respiration was determined by incubating the soils amended with glucose at different water contents and measuring the respiration for 10 days at 25ºC. Glucose...

Response of microbial activity and biomass to changes in soil salinity and water content.

Yan, Nan
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
36.76%
Salinization is a serious land degradation problem because osmotic stress and toxic ions cause poor plant growth and low soil microbial activity. The effect of salinity on soil microbes has been studied previously, but usually at constant salinity. However, in the field salinity may vary over time. Another factor influencing the effect of salinity on soil microbes is the soil water content. The osmotic potential, which is a measure of the salt concentration in the soil solution, increases as soils dry. The aim of the experiments described in this thesis was to assess how soil microbial activity and microbial biomass respond to changes in soil salinity and soil water content. One non-saline and four saline soils from Monarto, South Australia (35° 05´ S and 139° 06´ E) were used in the experiments. Soils were air-dried after collection. In some experiments, salinity was induced by adding certain amount of NaCl (dissolved in RO water), or decreased by leaching. Preliminary experiments were carried out to quantify the salts or water needed to reach the desired salinity. Pea (Pisum sativum L.) straw (C/N=26) was used as available substrate in most experiments except for experiments in Chapter four, where glucose was used. Soil CO₂ release (respiration as measure of microbial activity) was measured daily throughout each experimental period...

Forest resources in Graciosa Island (Azores) : biomass availability for sustainable energetic use

Teixeira, Ana Isabel de Carvalho
Fonte: Universidade dos Açores Publicador: Universidade dos Açores
Tipo: Dissertação de Mestrado
Publicado em 09/02/2015 ENG
Relevância na Pesquisa
36.79%
Dissertação de Mestrado em Ambiente, Saúde e Segurança.; Master dissertation included in the project: "Recursos Florestais da Ilha Graciosa, Açores" from Fundação Gaspar Frutuoso, with Financial Support from Graciólica, Lda And Younicos Ag.; O potencial da biomassa para a produção de energia tem sido amplamente estudado, e recentemente, ganhou um novo ímpeto com a atenção agora dirigida às energias renováveis. A biomassa florestal pode ser utilizada como matéria-prima em diferentes tipos de aplicações energéticas. Nos Açores, e em particular na Ilha Graciosa, a área ocupada por povoamentos florestais é relativamente pequena; no entanto, áreas consideráveis estão ocupadas por bosques de exóticas, maioritariamente dominados por Pittosporum undulatum Ventenat (Pittosporaceae). O objetivo deste trabalho é avaliar a biomassa lenhosa existente na Ilha Graciosa, principalmente de P. undulatum, de modo a avaliar a sua disponibilidade para a utilização energética. Foi feito trabalho de campo na Ilha Graciosa de modo a obter dados dendrométricos de P. undulatum e da biomass viva acima do solo de árvores recentemente cortadas com o propósito de determinar equações alométricas específicas para P. undulatum...

Exploring TM image texture and its relationships with biomass estimation in Rondônia, Brazilian Amazon

Lu,Dengsheng; Batistella,Mateus
Fonte: Instituto Nacional de Pesquisas da Amazônia Publicador: Instituto Nacional de Pesquisas da Amazônia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2005 EN
Relevância na Pesquisa
36.76%
Many texture measures have been developed and used for improving land-cover classification accuracy, but rarely has research examined the role of textures in improving the performance of aboveground biomass estimations. The relationship between texture and biomass is poorly understood. This paper used Landsat Thematic Mapper (TM) data to explore relationships between TM image textures and aboveground biomass in Rondônia, Brazilian Amazon. Eight grey level co-occurrence matrix (GLCM) based texture measures (i.e., mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment, and correlation), associated with seven different window sizes (5x5, 7x7, 9x9, 11x11, 15x15, 19x19, and 25x25), and five TM bands (TM 2, 3, 4, 5, and 7) were analyzed. Pearson's correlation coefficient was used to analyze texture and biomass relationships. This research indicates that most textures are weakly correlated with successional vegetation biomass, but some textures are significantly correlated with mature forest biomass. In contrast, TM spectral signatures are significantly correlated with successional vegetation biomass, but weakly correlated with mature forest biomass. Our findings imply that textures may be critical in improving mature forest biomass estimation...

Surface and subsurface decomposition of a desiccated grass pasture biomass related to erosion and its prediction with RUSLE

Cogo,N. P.; Streck,E. V.
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2003 EN
Relevância na Pesquisa
36.76%
Erosion is deleterious because it reduces the soil's productivity capacity for growing crops and causes sedimentation and water pollution problems. Surface and buried crop residue, as well as live and dead plant roots, play an important role in erosion control. An efficient way to assess the effectiveness of such materials in erosion reduction is by means of decomposition constants as used within the Revised Universal Soil Loss Equation - RUSLE's prior-land-use subfactor - PLU. This was investigated using simulated rainfall on a 0.12 m m-1 slope, sandy loam Paleudult soil, at the Agriculture Experimental Station of the Federal University of Rio Grande do Sul, in Eldorado do Sul, State of Rio Grande do Sul, Brazil. The study area had been covered by native grass pasture for about fifteen years. By the middle of March 1996, the sod was mechanically mowed and the crop residue removed from the field. Late in April 1996, the sod was chemically desiccated with herbicide and, about one month later, the following treatments were established and evaluated for sod biomass decomposition and soil erosion, from June 1996 to May 1998, on duplicated 3.5 x 11.0 m erosion plots: (a) and (b) soil without tillage, with surface residue and dead roots; (c) soil without tillage...

Aboveground biomass assessment in Colombia: A remote sensing approach

Anaya J.A.; Chuvieco E.; Palacios-Orueta A.
Fonte: Universidade de Medellín Publicador: Universidade de Medellín
Tipo: Article; info:eu-repo/semantics/article
ENG
Relevância na Pesquisa
36.77%
This paper presents a method to increase the level of detail of aboveground biomass estimates at a regional scale. Methods are based on empirical relationships while materials are based on MODIS products and field measurements; the area covers from 4° south up to 12° north of the Equator with a total of 1,139,012 km 2 corresponding to the continental area of Colombia. Vegetation was classified in three broad classes: grasslands, secondary forests and primary forests which have been proved to enhance biomass estimates. MOD44 vegetation continuous fields (VCFs) was used as an explanatory variable for primary and secondary forests following an exponential relationship, while MOD13A1 enhanced vegetation index (EVI) was used as explanatory variable for grasslands following a linear relationship; biomass for this vegetation class was estimated every 16 days given its large variation throughout the year. EVI-biomass relationships were established from 2001 to 2006. Vegetation maps were used to separate primary forests from secondary forest, since the latter has shown lower biomass levels. Confidence intervals of the exponential regression are larger as the biomass values increases, for this reason the uncertainty is quite high ranging from 3.7 to 25.2 millions of Mg with a mean of 16.2 million of Mg. Despite the uncertainty our biomass results are within the estimates of previous studies. © 2008 Elsevier B.V. All rights reserved.

Characteristics of high heating rate biomass chars prepared under N2 and CO2 atmospheres

Gómez Borrego, Ángeles; Garavaglia, L.; Kalkreuth, W. D.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
36.76%
7 pages, 6 figures, 3 tables. -- Available online 4 July 2008. -- Issue title: CSCOP-TSOP-ICCP 2007: Selected papers from the 2007 joint meeting of CSCOP-TSOP-ICCP: Unconventional petroleum systems & advances in organic petrology and geochemistry (Victoria BC, Sunday, August 19th to Saturday August 25th, 2007); Partial substitution of coal by biomass in combustion systems in conjunction with advanced technologies for CO2 capture and storage may result in a significant reduction of greenhouse gases emissions. This study investigates three biomass chars produced from rice husk, forest residuals and wood chips under N2 and CO2 atmospheres using a drop tube furnace (DTF) heated at 950 °C. The char constitutes an unburned residue which has been devolatilized under conditions resembling in thermal history those in full scale boilers. Higher weight losses were achieved under N2 than under CO2 for each type of biomass, and the highest weight loss was that of wood chips biomass, followed by forest residuals and then rice husk. The results indicate significant morphological differences between the biomass chars produced. The wood chips yielded thick-walled chars with a cenospheric shape very similar to those of low-rank vitrinite. The forest residual chars were angular in shape and often had a tenuinetwork structure...

A Biomass Fuel Assessment for Duke University’s Chilled Water Plant #2

Crowley, Richard
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project Formato: 798502 bytes; application/pdf
EN_US
Relevância na Pesquisa
36.76%
This Masters Project identifies the University’s biomass fuelshed and locates potential supply sources and probable fuel quantities. An Excel workbook couples user-defined transportation, processing, collection and handling, and purchase premium expenses within fuel classes to establish probable purchase costs for each supply source. Results are optimized for a lowest cost fuel mix to meet modeled plant demand based on user defined plant parameters. Finally, total biomass fuel costs are compared to fossil options to determine if biomass is a financially justifiable fuel for Duke to pursue. The results of this study indicate that the university fuelshed likely contains supply for more than 4 times the steam plants fuel requirements. The cost per million British thermal units combusted within the fuelshed is highly variable, ranging from approximately $1.01 for construction / demolition material to over $29 for forest thinnings. Several fuel classes are more economic than current prices for natural gas, ranging from less than a quarter to three quarters of the price of natural gas. The preliminary assessments of purchasing biomass fuel for use in the plant resulted in costs significantly lower than natural gas, and even potentially lower than coal. It is anticipated that the annual fuel costs for a biomass plant could be met for around $2.25 million based on plant parameters modeled and the estimated biomass characteristics (collection...

Quantification of Biomass Potential from Timber Stand Improvement (TSI) Operations in Hardwood Stands in North Carolina

Rutledge, Matthew
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 08/12/2011
Relevância na Pesquisa
36.79%
Across North Carolina, forest species composition has changed substantially over the past 35 years. Oak species have declined while other species, especially red maple and sweetgum have proliferated. This general trend is seen across the state of North Carolina, though each of the four physiographic regions of the state has different factors that contribute to the specie composition changes. Within oak stands, competition in the understory and midstory can significantly reduce oak regeneration. Mitigating competition with oak species through TSI can generate biomass for energy. This project explores potential connections between oak regeneration through conservation forestry and timber stand improvement operations that target red maple and sweetgum removals for biomass energy. This project quantifies small-diameter biomass of red maple and sweetgum trees in oak dominated stands across North Carolina. Biomass supply estimates typically focus on available residues from forest harvests or from overstocked stands. This report is the first to focus on biomass available from restoration activities in hardwood stands. The standing stock of small diameter red maple and sweetgum is approximately 18,000,000 tons in North Carolina, or 725...

Direct conversion of microalgae biomass to biocrude with hydrothermal liquefaction.

Eboibi, Blessing Elo-oghene
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2015
Relevância na Pesquisa
36.82%
Microalgae are generally considered as a promising biomass source for applications including production of advanced biofuels, chemicals, wastewater treatments, various organic substances or a combination of any of the above. The advantages of microalgae includes faster growth rates than terrestrial plants, ability to use non-arable land for mass production, and their ability to grow in poor quality water, as well as their ability to remove pollutants from wastewater streams. However, one of the major challenges of microalgae for commercialisation to is its economic downstream production and conversion to biofuels and chemicals. When harvested, microalgae contains up to ~90% water content, thus economic conversion of high moisture content biomass to valuable products such as biofuels remains a challenge. Hydrothermal liquefaction (HTL) involves processing of high moisture content biomass in hot compressed water, avoiding the drying step for biomass feedstocks. Therefore HTL is advantageous as it avoids the energy intensive drying process in contrast to processes that involve drying of biomass prior to processing into biofuels. HTL products comprise biocrude, solid residues, aqueous and gas phases. The primary product biocrude is upgradable to liquid transportation fuels. The aqueous phase contains essential nutrients that could be recycled to microalgae cultivation ponds. The gas phase contains about 98mol% carbon dioxide (CO₂) and 2mol% hydrocarbon gases. The gas phase can also be directly recycled to the microalgae cultivation ponds for pH control and supply of CO₂...