The usage of crop residues, among other lignocellulosic biomass, has being considered a promising alternative feedstock for bioenergy (i.e., second generation ethanol - ethanol 2G and bioelectricity) production. With the adoption of sugarcane-mechanical harvesting in Brazil, in average 15 Mg ha-1 of straw are left on the field annually. Partial straw removal for bioenergy production has become a common practice, while partial straw retention on the field ensures several benefits for the soil-plant system. Efforts have being done in order to establish the best route to straw recovery from the field and defining the amount which meeting both needs. Thus, the aims of this study were: i) to establish a step-by-step guidelines to straw recovery from the field; ii) to determine the implications of increasing rates of straw removal on plant growth, stalk yield and stalk industrial quality; iii) to evaluate the effectiveness of straw-blanket raking practice on plant growth and yield, and iv) to use Soil Management Assessment Framework (SMAF) as a tool to perform an integrated approach of soil quality (SQ) under different rates of straw removal. To achieve the proposed goals, a 2-years experiment was set up within the dry and wet seasons at Valparaíso and Capivari, São Paulo, locations with different edaphoclimatic conditions. Increases of primary extractor fan\'s velocity on the harvester lead to placement and removal of straw rates proportionally to 0, 25, 50, 75 e 100%. After two years, parameters associated to the soil- chemical [(Phosphorus-P, Potassium-K and pH), physical-(bulk density) and biological- (microbial biomass carbon-MBC and SOC)] attributes were analyzed within the 0-5, 5-10, 10-20 and 20-30 cm. Under colder climatic condition, plant tillering improved by the increasing rates of straw removal, however plant growth and stalk yield are slightly affected by the straw management. Stalk harvested in the dry season presented higher industrial quality than those harvested within the wet season but this parameter is unaffected by straw removal. Further, under colder climatic condition, to rake the straw blanket enhanced plant tillering while plant growth and stalk yield were not influenced by raking the straw blanket. No straw removal increases P content on plant tissue, regardless of blanket management, especially under the poorest inherent soil condition. The SMAF tool was able to detect changes on soil quality under different rates of straw removal and Oxisol responds faster to straw removal management than Ultisol in the short term. Total straw removal leaded to Oxisoil physical quality degradation; among the soil attributes, soil-physical attribute within the 0-10 cm is correlated with stalk yield. The partial straw removal for bioenergy production leads to the optimization on sugarcane biomass usage. However, the appropriate rate of straw to be removed is site specific and ranged 4-9 Mg ha-1 under the conditions in which this study was performed. The stalk yield was unaffected by raking the straw blanket. The monitoring of SOC, adoption of traffic controller and application of subproducts from the sugarcane industry are strategies to increase soil quality and, consequently, the sustainability of the crop cultivation. / O uso de resíduos culturais, dentre outros tipos de biomassa lignocelulósica, tem sido considerado uma alternativa promissora para produção de bioenergia (etanol de segunda geração e bioeletricidade). Com a implementação da colheita mecanizada da cana-de-açúcar no Brasil, em média 15 Mg ha-1 palha são deixadas no campo anualmente. A utilização de parte deste resíduo para produção de bioenergia tem se tornado uma prática comum, enquanto a manutenção de parte da palha no campo viabiliza vários benefícios ao sistema solo-planta. Esforços têm sido feitos a fim de estabelecer a melhor rota para remoção da palha do campo e definir a quantidade que atenda ambas demandas. Assim, os objetivos deste estudo foram: i) estabelecer um guia que viabilize a remoção de diferentes taxas de palha; ii) determinar as implicações oriundas da remoção de taxas de palha no crescimento, produtividade e qualidade tecnológica de colmos; iii) avaliar a eficácia do enleiramento da camada de palha sobre o crescimento e produtividade da cultura e, iv) utilizar Soil Management Assessment Framework (SMAF) como ferramenta para avaliar de modo integrado os efeitos da remoção de diferentes taxas de remoção de palha sobre a qualidade do solo (QS). Para tanto, foram conduzidos quatro ensaios, sendo um na estação seca e outro na estação úmida em dois locais: Capivarí e Valparaíso, SP; locais com diferentes condições edafoclimáticas. Crescentes rotações no extrator primário da colhedora viabilizaram a deposição e remoção de taxas de palha proporcionais a 0, 25, 50, 75 e 100%. Após dois anos, análises de parâmetros associados aos atributos químicos [(P, K, pH), físicos (densidade) e biológicos (carbono da biomassa microbiana - MBC e SOC)] do solo foram realizadas nas profundidades 0- 5, 5-10, 10-20 e 20-30 cm. Em condições climática mais fria, a remoção de crescentes quantidades de palha melhora o perfilhamento da cultura; entretanto, o crescimento e produtividade de colmo são pouco afetadas pelo manejo da palha. A qualidade tecnológica de colmos colhidos na época seca é superior aos colhidos na época úmida, entretanto, este parâmetro não é afetado pela remoção de crescentes quantidades de palha. Sobre condições climática mais fria, o perfilhamento é beneficiado pelo enleiramento da palha, ao passo que tanto o crescimento quanto a produtividade são insensíveis à essa prática. A retenção da palha aumenta o conteúdo de P no tecido vegetal, especialmente em solo naturalmente pouco fértil. A SMAF foi capaz de detectar alterações na QS em função da remoção de taxas de palha; sendo o Latossolo Vermelho distrófico típico o mais afetado pela remoção da palha em relação ao Argissolo Vermelho- Amarelo distrófico típico em curto prazo. A remoção total da palha promoveu degradação física do primeiro tipo de solo; dentre os atributos do solo avaliados, o atributo físico na profundidade 0-10 cm está correlacionado com a produtividade da cultura. A remoção parcial da palha de canade- açúcar para produção de bioenergia promove otimização no uso da biomassa da cultura. Entretanto, a taxa de palha a ser removida é intrínseca para cada local e variou de 4-9 Mg ha-1 neste estudo. A produtividade é insensível ao enleiramento da palha. O monitoramento nos teores de carbono do solo, a adoção do controle de tráfego de máquinas e a aplicação de resíduos da agroindústria canavieira podem ser estratégias adotadas para melhorar a QS e, por consequência, a sustentabilidade de cultivo da cana-de-açúcar.

Resumo: O objetivo do presente trabalho foi avaliar diferentes sistemas de preparo do solo: Plantio Convencional (PC), Cultivo Mínimo (CM) e Plantio Direto (PD), dois níveis de palhada remanescente da cana-de-açúcar colhida mecanicamente, nos atributos físicos do solo, crescimento radicular e componentes de produtividade do amendoim. As cultivares IAC Tatu ST e Runner IAC 886 foram semeados no dia 23 de novembro de 2007, em Latossolo Vermelho distrófico no município de Guariba (SP). O delineamento experimental utilizado foi em blocos casualizados, com parcelas subsubdivididas com seis repetições. Os tratamentos foram constituídos por três diferentes sistemas de preparo do solo, dois níveis de palhada (sem e com) e três profundidades de coleta de solo: 0,03-0,06; 0,13-0,16 e 0,23-0,26 m, para determinação da resistência mecânica do solo à penetração, densidade e porosidade do solo, bem como, a determinação da estabilidade de agregados e crescimento radicular nas profundidades de 0-0,1 e 0,1-0,2 m. Os maiores valores de densidade do solo, resistência mecânica do solo à penetração e menor valor de macroporosidade encontrados no PD na camada mais superficial, influenciaram negativamente o crescimento radicular. A densidade de 1,44 Mg m-3 e resistência mecânica do solo à penetração de 1,56 MPa encontradas no PC na camada de 0,13-0,16 m limitou o crescimento das raízes abaixo dessa camada. O PD e o CM proporcionaram maior agregação do solo com relação ao PC, nas duas camadas avaliadas. Os sistemas de preparo onde as 15 t ha-1 de palhada remanescentes da cana-de-açúcar permaneceram sobre a superfície do solo sem incorporação, influenciou negativamente a produtividade e rendimento dos grãos do amendoim para os dois cultivares. / Abstract: The aim of this study was evaluate different soil tillage systems: conventional tillage (CT), chisel tillage (CHT) and no-tillage (NT) with and without straw remainder of sugarcane harvested mechanically, the soil physical properties, root growth and peanuts yield. The cultivars IAC Tatu ST and Runner IAC 886 were sowed in Haplustox on 27 november 2007 in the town Guariba-SP. Randomized complete block design in split-split- plots with six replications were used. Three different tillage systems, two straw level (with and without) and three depths: 0.03-0.06; 0.13-0.16 and 0.23-0.26 m, for determining the soil mechanical resistance to penetration, density and porosity. For determine root density, root surface, root diameter and root dry mass, soil samples were collected in two layers (0-0.10 and 0.10-0.20 m). Most value soil density, mechanical resistance to penetration and smaller values macroporosity found NT superficial soil layer negatively influenced root growth. The density of 1.44 Mg m-3 and mechanical resistance to penetration of 1.56 MPa found in the CT layer 0.13-0.16 m limited the roots growth downwards this layer. In the two layers evaluated, the NT and CHT provided greater soil aggregation in relation CT. The tillage systems where 15 t ha- 1 sugarcane straw remnants remained on the soil surface without incorporation, prevented the gynophore penetration in to soil negatively influency peanut productivity and grain yield / Orientador: Maria Aparecida Pessôa da Cruz Centurion / Coorientador: José Frederico Centurion / Banca: Gisele Herbst Vazquez / Banca: Edson Lazarini / Banca: Marlene Cristina Alves / Banca: Itamar Andrioli / Doutor

Orientador: Edson Lazarini / Banca: Salatiér Buzetti / Banca: Dirceu Maximino Fernandes / Resumo: O potássio (K) é o segundo nutriente requerido em maior quantidade pela cultura da soja. Com a utilização de altas doses de potássio na semeadura da soja em solos com baixa Capacidade de Troca Catiônica (CTC) e precipitação pluvial intensa ocorrem perdas de K+ por lixiviação, necessitando de um melhor manejo dessa adubação. As plantas de cobertura podem ser opções eficientes para a reciclagem de K+ do solo e disponibilização gradativa à cultura subsequente. Nesse sentido, objetivou-se com o presente trabalho avaliar o efeito da antecipação da adubação potássica da soja em culturas de cobertura para a produção de palha e disponibilização gradativa de potássio para a soja em sucessão, em semeadura direta num Latossolo Vermelho distrófico argiloso (LVd) na região de cerrado, em comparação às aplicações usuais na semeadura e/ou em cobertura. O experimento foi conduzido no ano agrícola 2009/2010 na área experimental da Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia/UNESP - Campus de Ilha Solteira, localizada no município de Selvíria -MS. O delineamento experimental foi em blocos ao acaso, com os tratamentos dispostos em esquema fatorial 3x3x5, com quatro repetições. Os fatores consistiram de culturas de cobertura (milheto e painço) e um controle (pousio), doses de K2O (0, 50 e 100 kg ha-1) e formas de aplicação de K2O (100% na semeadura das culturas de cobertura; 100% na semeadura da soja; 100% em cobertura na soja; 50% antecipada nas culturas de cobertura + 50% na semeadura da soja; 50% na semeadura da soja + 50% em cobertura na soja). Foram avaliadas as seguintes variáveis: Estado nutricional e massa seca das culturas de cobertura, estado nutricional das plantas de soja, altura de plantas, altura de inserção de primeira vagem, número de vagens por planta e grãos por vagem, produtividade de grãos, massa de 100 grãos e teor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The potassium is the second nutrient required in greater quantity by crop soybean. With the utilization of high doses of potassium in soybean sowing in soils with low Cationic Exchange Capacity (CEC) and intense rainfall occurs losses of K+ by leaching, requiring better management of fertilizer. Cover crops can be efficient options for the recycling of K the soil and gradual availability to subsequent crop. In this sense, aimed to evaluate the effect of anticipation potassium fertilization of soybean in cover crops for the production of straw and gradual availability of potassium soybean in succession, in no-tillage in a clayey Distrofic Red Latosol, in savannah, comparing to the usual applications at sowing and/or cover. The experiment was conducted in the crop season 2009/2010, in the experimental farm of São Paulo State University, campus of Ilha Solteira, located in Selvíria, state of Mato Grosso do Sul, Brazil. The experimental design was randomized blocks, with treatments arranged in a factorial scheme 3x3x5, with four replications. The factors consisted of cover crops (Pennisetum glaucum and Panicum miliaceum) and a control (fallow area), doses of K2O (0, 50 e 100 kg ha-1) and application forms of K2O (100% at sowing of cover crops; 100% at sowing of soybean; 100% at cover in soybean; 50% at sowing cover crops + 50% at sowing of soybean; 50% at sowing of soybean + 50% at cover in the soybean). We evaluated the following variables: nutritional state and dry matter of cover crops, nutritional state of soybean plants, plant height, height of insertion of first pod, number of pods per plant and grains per pod, grains productivity , mass 100 grains and macronutrient content in soybean seeds. The pearl millet as cover crop soybean predecessor, had dry matter and potassium content higher than the proso millet, independent of dose and application form of K2O. In soil with high potassium... (Complete abstract click electronic access below) / Mestre

Este trabalho avaliou a extração de xilose da palha de cana-de-açúcar sob diferentes condições de hidrólise por ácido sulfúrico diluído visando à obtenção de um hidrolisado hemicelulósico rico em xilose e ainda a fermentabilidade deste para a bioconversão a etanol por Pichia stipitis Y-7124. Inicialmente caracterizou-se a palha de cana e a fração hemicelulósica representou 30,79% da massa seca da palha, enquanto que a celulose representou 40,84% e a lignina 25,80%. Verificou-se ainda que 26,57% da palha corresponde à xilose, representando 86,27% de sua fração hemicelulósica. As hidrólises ácidas foram realizadas de acordo com um planejamento experimental fatorial fracionado 24-1 visando-se à resposta concentração de xilose (g/L) no hidrolisado hemicelulósico. Levou-se em consideração os fatores: tempo, temperatura, concentração da solução ácida e a relação sólido:líquido. A melhor resposta para a concentração de xilose foi encontrada nas condições do ponto central, com a média da concentração igual a 31,70 g/L. A análise de variância foi realizada para um screening do planejamento e observou-se que apenas os fatores concentração da solução ácida e temperatura foram significativos ao nível de 95% de confiança. Em seguida realizou-se ensaios para otimização da hidrólise ácida considerando os fatores temperatura e concentração da solução ácida. As condições de ótimo encontradas foram 130 ºC e a solução de ácido sulfúrico em 2,9% m/v, empregadas com uma relação sólido:líquido igual a 1:4 (g/mL) por 30 minutos de reação. Estas condições de ótimo permitiram a obtenção de um hidrolisado hemicelulósico com concentração igual a 56,5 g/L de xilose, correspondendo à extração de 85,1% da xilose da palha. Posteriormente, ensaios de fermentação foram conduzidos com o hidrolisado hemicelulósico obtido, visando à produção de etanol por P. stipitis em frascos Erlenmeyer de 250 mL com 100 mL de meio hidrolisado para avaliar a fermentabilidade do hidrolisado obtido bem como a necessidade de suplementação nutricional e utilizou-se um planejamento experimental fatorial 23 de face centrada para verificar a influência dos fatores: concentração de ureia, concentração de MgSO4*7H2O e concentração de extrato de levedura. Os ensaios foram conduzidos a 200 rpm e 30 ºC. Verificou-se que o extrato de levedura (5 g/L) exerceu maior influência sobre o processo fermentativo e que o MgSO4*7H2O (0,5 g/L) não apresentou significância estatística. A melhor condição na fermentação para produção de etanol por P. stipitis encontrada foi empregando-se extrato de levedura (5 g/L), ureia (5 g/L) e MgSO4*7H2O (1,0 g/L), em que se obteve um fator de rendimento em etanol YP/S igual a 0,38 g/g e produtividade volumétrica igual a 0,41 g/L.h, em 60 horas de fermentação. / This work evaluated the sugar cane straw xylose extration under different diluted sulfuric acid hydrolysis conditions aiming at the attainment of hemicellulosic hydrolysate rich in xylose and their fermentability for ethanol bioconversion by Pichia stipitis Y 7124. Previous assays for chemical characterization of the sugar cane straw has been carried. The hemicellulosic fraction represented 30.79% of the dry straw mass, whereas the cellulose represented 40.84% and the lignin represented 25,80%. It was verified despite 26,57% of the straw corresponded to xylose, representing 86,27% of its hemicellulosic fraction. The acid hydrolysis was carried out using an experimental design 24-1 aiming at it the xylose concentration (g/L) response on the hemicellulosic hydrolysate regarding the factors: time, temperature, acid solution concentration and the ratio solid:liquid. The best result for the xylose concentration has been found on the center point conditions, with concentration of 31,70 g/L. The analysis of variance was carried out to one screening of the design and it was observed that only the parameters temperature and acid solution concentration has been significant at 95% reliable level. After that acid hydrolysis assays has been carried regarding the factors temperature and acid solution concentration aiming the acid hydrolysis optimization. The optimum point conditions were 130 ºC and the sulfuric acid solution of 2,9% m/v, carried with the ratio solid:liquid of 1:4 (g/mL) at 30 minutes of reaction. Later, fermentation assays was carried out with the hemicellulosic hydrolysate obtained in 250 mL Erlenmeyer flasks containing 100 mL of hydrolysate to evaluate the hydrolysate fermentability obtained as well tha needless of nutritional supplementation and for it used an experimental design 23 of face centered to verify the influence of the factors: urea concentration, MgSO4*7H2O concentration and yeast extract concentration. Assays has been carried at 30 ºC and 200 rpm. It was verified that the yeast extract (5 g/L) exerts greater influence on the fermentation and the MgSO4*7H2O (0,5 g/L) did not present statistic significance. The best conditions were achieved using yeast extract (5 g/L), urea (5 g/L) and MgSO4*7H2O (0,5 g/L). with ethanol yield and volumetric productivity of 0,38 g/g and 0,41 g/L.h, respectively, after 60 hours of fermentation.

Copies of the author's previously published articles inserted. Bibliography: leaves 142-159. Provides information on the significance of pea straw as a ruminant feed and the potential of two biological techniques for improving its feeding value.

Road traffic dominates in domestic Swedish transportation and is highly dependent on fossil fuels, petrol and diesel. Currently, the use of renewable fuels in transportation accounts for less than 6% of the total energy use in transport. The demand for bioethanol to fuel transportation is growing and cannot be met through current domestic production alone. Lignocellulosic ethanol derived from agricultural crop residues may be a feasible alternative source of ethanol for securing a consistent regional fuel supply in Swedish climatic conditions.  This licentiate thesis focuses on regional transport fuel supply by considering local small-scale ethanol production from straw. It presents the results of investigations of regional transport fuel supply with respect to minimising regional CO2 emissions, cost estimates for transport fuel supply, and the availability of lignocellulosic resources for small-scale ethanol production. Regional transport fuel demand between the present and 2020 is also estimated. The results presented here show that significant bioethanol can be produced from the straw and Salix available in the studied regions and that this is sufficient to meet the regions’ current ethanol fuel demand.  A cost optimisation model for regional transport fuel supply is developed and applied for two cases in one study region, one when the ethanol production plant is integrated with an existing CHP plant (polygeneration), and one with a standalone ethanol production plant. The results of the optimisation model show that in both cases the changes in ethanol production costs have the biggest influence on the cost of supplying the regional passenger car fleet with transport fuel, followed by the petrol price and straw production costs.  By integrating the ethanol production process with a CHP plant, the costs of supplying regional passenger car fleet with transport fuel can be reduced by up to a third. Moreover, replacing petrol fuel with ethanol can cut regional CO2 emissions from transportation by half.

Preparation of thermoplastics composites using engineering thermoplastics and plant fibers or fillers is a technical challenge because the processing temperature of the thermoplastics is generally above the temperature of degradation of plant fibers of fillers. There have been numerous attempts for processing high melting point engineering thermoplastics like Nylon-6 with plant natural fibers and fillers. Low temperature processing methods, fiber modification or addition of additives which drops polymer melting point are some of proposed solutions for this problem. The objective of this thesis was to develop a formulation using wheat straw (WS) as a reinforcing fiber for Nylon-6. The concentration of WS was 15 wt-%. The thermoplastic composites were prepared by mixing grinded wheat straw and Nylon-6 using a laboratory scale twin-screw extruder; follow by preparation of samples using injection moulding. The strategy investigated in this thesis was utilization of additives to lower the melting point or to decrease the viscosity of Nylon-6. Lithium chloride salt (LiCl) and N-Butyl benzene Sulfon amide plasticizer (N-BBSA) were used as process additives to decrease melting point and to reduce the processing temperature and time. The addition of the wheat straw (15 wt-%) to the Nylon-6 increased modulus by 26.9 % but decreased the strength by 9.9 %. Effect of different level of these two additives on mechanical, thermal, physical properties and processability of the composite runs were studied. Addition of 4 wt-% LiCl was found to decrease the melting point from 222 °C to 191 °C, to increase modulus by 14 % in comparison to Nylon-6/wheat straw (15 wt-%). However, it decreased the processability and strength by 12.7 %. Plasticizer was investigated to easing processability and decreasing the degradation by reducing the residence time in the extruder, it does not affect the melting point of Nylon-6. The addition of 4 wt-% of plasticizer (N-BBSA) increased modulus and strength only by 2.6 % and 3 %, respectively, in comparison to Nylon-6/wheat straw (15 wt-%) composites. The results of mechanical properties were used as a benchmark for comparisons among samples with different formulations (levels of additives) to find out levels of LiCl and N-BBSA for the best mechanical properties. It was found that samples with 2 wt-% LiCl and 2 wt-% of N-BBSA had 29.3 % higher tensile modulus than neat Nylon-6, while its strength was almost same as neat Nylon-6 and 6.3 % higher than Nylon-6/WS (15 wt-%). These results were used to correlate the mechanical properties as a function of percentage of salt and plasticizer in the formulation. Differential scanning calorimetry (DSC) was used to evaluate the percentage of crystallinity and the melting point of the thermoplastic phase and thermal gravimetric analysis (TGA) was used to measure the thermal stability of different formulation. The kinetics of crystallization and degradation were evaluated using results from DSC and TGA, respectively. The activation energy for thermal degradation and the percentage of crystallinity of the thermoplastic composites were correlated to mechanical properties using linear regression. It was found that fiber degradation had a significant effect on strength but the effects of percentage of crystallinity on composites strength were insignificant. On the other hand, the percentage of crystallinity affects stiffness and impact strength. The ductility was a function of both crystallinity and thermal stability.

American publishers of indecent books from 1840 to 1890 were not outsiders to the printing trades. They should be seen instead as entrepreneurs whose technological practices and business strategies were largely representative of the diversity within American publishing. Books prohibited or later destroyed because of their content survived in a relatively wide variety of forms in the hands of rare book collectors, making such artifacts perhaps even more important for the study of industrial practices than literary works collected in greater numbers by research institutions. Those rare artifacts make available long-lost details about the men and women who manufactured print at the boundaries of social propriety, the production technologies they employed, and the place of difficult-to-research publishers in the American book trades. Conservation, papermaking, illustrations, printing, and typefounding are as important to the history of American erotica as the more famous prosecutions led by Anthony Comstock. Focusing on works considered indecent by the nineteenth-century bibliographer Henry Spencer Ashbee, this dissertation integrates the political economy of print with an analysis of the material forms of semi-erotic and obscene books. Surviving artifacts offer evidence about regional production styles and the ways that fiber selection, and particularly the use of straw in low-quality papers, influenced the prevalence of yellow wrappers for ephemeral works. Printer skill levels and capitalization can sometimes be determined through the presence of gripper marks on printed sheets. Reconstructing and contextualizing the technological practices of these publishers can create new tools for bibliographical analysis, an accessible source of information about technical processes for general historians, and a wealth of data about publishers such as William Berry, whose role in networks of erotica in nineteenth-century America has only recently begun to be appreciated.

Zielstellung des Forschungsprojekts ist es, halm- und stengelförmige biogene Brennstoffe so zu einer handlings- und verkaufsfähigen Form mit hoher Energiedichte aufzubereiten, die für Verbrennungsanlagen kleinerer Leistung geeignet ist und gegenüber bisher verwendeten Brennstofformen, z.B. Häcksel, eine wesentliche Verbesserung des Abbrand-, Emissions- und Ascheverhaltens erreicht wird. Ein Funktionsmuster zur kontinuierlichen Aufbereitung von hochverdichteten, abriebfesten und formstabilen Briketts ist zu erstellen. In Kopplung mit Verbrennungsuntersuchungen werden die spezifischen Anforderungen an die Briketts abgeleitet und der Verfahrensablauf für die Aufbereitung optimiert. Bei der Erstellung eines Konzeptes für ein Demonstrationsobjekt für die zukünftige Verwertung von Biomassebriketts bildet die Wirtschaftlichkeit einen besonderen Schwerpunkt. Die Arbeiten zur Entwicklung des Brikettierverfahrens zeigen, daß eine Herstellung von stabilen Briketts aus Stroh oder Heu ohne zusätzliche Bindemittel möglich ist. Mit Hilfe experimenteller Untersuchungen konnten die erforderlichen Verfahrensparameter ermittelt werden. Um dauerhaft haltbare Briketts gleichbleibender Qualität herzustellen, muß das zu verarbeitende Halmgut unzerkleinert und mit einem Feuchtegehalt von 12 bis 15 % vorliegen. In der Verformung der unzerkleinerten Halme sowohl in Längsrichtung als auch in der Ebene des Stengelquerschnitts ist die Ursache für den Bindemechanismus in den Briketts zu finden. Unter Einwirkung von Preßdrücken von 100 bis 160 MPa liegt die Dichte der hergestellten Briketts je nach Gutart, bei 0,8 bis 1,2 g/cm3. Der Abriebanteil der Briketts, ermittelt nach ASAE S.269.4, liegt bei max. 5%. Ein Funktionsmuster zur Brikettierung (Brikettpresse mit vorgeschalteter Strangformungsstufe) für 25-mm - Briketts wurde konstruiert, gebaut und getestet. Mittels Elementar-, Immediat-, Chlor- und Schwermetallanalyse wurden die Eigenschaften für zehn verschiedene biogene Brennstoffe, vorwiegend Halmgüter (Getreide- und Rapsstroh, Wiesenheu, Miscanthus) charakterisiert. Die Abbranduntersuchungen der Briketts im Vergleich zum Häcksel zeigen, daß die Reaktionsphasen der Flüchtigenverbrennung und des Restkoksabbrandes gleichzeitig ablaufen. Eine wesentliche Verlängerung der Abbrandzeit ist zu verzeichnen, die mit zunehmender Brikettgröße und -dichte noch steigt. Während der gesamten Brennzeit werden die Schadstoffe gleichmäßig freigesetzt. Durch längere Verweilzeiten der Briketts im Reaktor wird der Kohlenstoffanteil des Brennstoffs vollständiger oxidiert, was sich in den wesentlich geringeren CO-Emissionen im Vergleich zum Häcksel widerspiegelt. Im Vergleich mit der TA Luft liegen die CO- und SO2-Emissionen der Biomassebriketts durchgängig unter den Grenzwerten. Durch eine luftgestufte Verfahrensführung (60% Primärluft, 40% Sekundärluft) ist es möglich, die NOx-Werte ebenfalls unter den Grenzwert der TA Luft abzusenken. Fallstudien zu möglichen Demonstrationsvorhaben belegen, daß eine wirtschaftliche Lösung für das Brikettieren in Verbindung mit einer energetischen Nutzung in kleinen Anlagen erreichbar ist. Die Leistung der Brikettieranlage bestimmt deutlich deren Wirtschaftlichkeit. Dabei muß eine Tagesproduktion von 8 bis 10 t erreicht werden (250 Betriebstage im Jahr). Gegenüber dem Funktionsmuster muß jedoch eine Vergrößerung des Brikettdurchmessers erfolgen.

Preparation of thermoplastics composites using engineering thermoplastics and plant fibers or fillers is a technical challenge because the processing temperature of the thermoplastics is generally above the temperature of degradation of plant fibers of fillers. There have been numerous attempts for processing high melting point engineering thermoplastics like Nylon-6 with plant natural fibers and fillers. Low temperature processing methods, fiber modification or addition of additives which drops polymer melting point are some of proposed solutions for this problem. The objective of this thesis was to develop a formulation using wheat straw (WS) as a reinforcing fiber for Nylon-6. The concentration of WS was 15 wt-%. The thermoplastic composites were prepared by mixing grinded wheat straw and Nylon-6 using a laboratory scale twin-screw extruder; follow by preparation of samples using injection moulding. The strategy investigated in this thesis was utilization of additives to lower the melting point or to decrease the viscosity of Nylon-6. Lithium chloride salt (LiCl) and N-Butyl benzene Sulfon amide plasticizer (N-BBSA) were used as process additives to decrease melting point and to reduce the processing temperature and time. The addition of the wheat straw (15 wt-%) to the Nylon-6 increased modulus by 26.9 % but decreased the strength by 9.9 %. Effect of different level of these two additives on mechanical, thermal, physical properties and processability of the composite runs were studied. Addition of 4 wt-% LiCl was found to decrease the melting point from 222 °C to 191 °C, to increase modulus by 14 % in comparison to Nylon-6/wheat straw (15 wt-%). However, it decreased the processability and strength by 12.7 %. Plasticizer was investigated to easing processability and decreasing the degradation by reducing the residence time in the extruder, it does not affect the melting point of Nylon-6. The addition of 4 wt-% of plasticizer (N-BBSA) increased modulus and strength only by 2.6 % and 3 %, respectively, in comparison to Nylon-6/wheat straw (15 wt-%) composites. The results of mechanical properties were used as a benchmark for comparisons among samples with different formulations (levels of additives) to find out levels of LiCl and N-BBSA for the best mechanical properties. It was found that samples with 2 wt-% LiCl and 2 wt-% of N-BBSA had 29.3 % higher tensile modulus than neat Nylon-6, while its strength was almost same as neat Nylon-6 and 6.3 % higher than Nylon-6/WS (15 wt-%). These results were used to correlate the mechanical properties as a function of percentage of salt and plasticizer in the formulation. Differential scanning calorimetry (DSC) was used to evaluate the percentage of crystallinity and the melting point of the thermoplastic phase and thermal gravimetric analysis (TGA) was used to measure the thermal stability of different formulation. The kinetics of crystallization and degradation were evaluated using results from DSC and TGA, respectively. The activation energy for thermal degradation and the percentage of crystallinity of the thermoplastic composites were correlated to mechanical properties using linear regression. It was found that fiber degradation had a significant effect on strength but the effects of percentage of crystallinity on composites strength were insignificant. On the other hand, the percentage of crystallinity affects stiffness and impact strength. The ductility was a function of both crystallinity and thermal stability.