Download or read book tude de la rh ologie de poudres de bois en vue de leur valorisation nerg tique written by Florent Thevenon and published by . This book was released on 2021 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: La biomasse peut être valorisée en énergie via de nombreux procédés. En particulier, la gazéification est un procédé de conversion thermochimique de la biomasse en un gaz de synthèse qui peut être ensuite transformé en biocarburants. La gazéification en réacteur à flux entraîné impose de broyer finement la ressource (quelques centaines de microns) afin d'assurer sa conversion totale dans le réacteur. Cependant, les poudres de biomasse sont composées de particules fines et allongées, ce qui induit une cohésion importante. Il en résulte des problèmes récurrents lors des opérations de stockage, de convoyage et d'injection de la matière. Dans ce contexte, ce travail de thèse vise à étudier la rhéologie des poudres de bois. L'approche expérimentale suivie est menée de l'échelle de la particule à l'échelle pilote. La première partie de la thèse présente l'étude de plusieurs chaines de préparation de poudres de bois à l'échelle pilote. Elles incluent soit une étape de torréfaction à 250 °C, soit un broyage additionnel à l'aide d'un broyeur vibrant. Le coût énergétique de production des poudres et leur coulabilité, mesurée à l'échelle laboratoire, sont comparés. Bien que la torréfaction réduise l'énergie nécessaire au broyage, le coût énergétique total de la chaîne incluant la torréfaction est très élevé par rapport à celui de la chaîne employant le broyeur vibrant. Cela est principalement dû au traitement des gaz de torréfaction dans la postcombustion. La valorisation de l'énergie des gaz de postcombustion dans les étapes de séchage et de torréfaction diminue de moitié les besoins en énergie et d'un quart les besoins en matière première. La torréfaction douce diminue d'un facteur deux le diamètre médian des particules mais ne modifie par leur forme. Le broyage dans le broyeur vibrant améliore la circularité des particules. Enfin, ces deux traitements améliorent significativement la coulabilité de la poudre dans des proportions similaires. Dans une deuxième partie de la thèse, la relaxation sous contrainte des poudres de bois est étudiée à l'échelle laboratoire avec une grande et une petite cellule de cisaillement. La lente relaxation de l'échantillon est interrompue par des variations soudaines et conséquentes, expliquées par un réarrangement collectif de grains. Ce phénomène est observé uniquement dans la plus grande cellule. Les réarrangements importants du milieu sont relativement indépendants de la contrainte normale appliquée et apparaissent à déformation constante du lit. L'amplitude de ces réarrangements ainsi que la déformation du lit entre deux réarrangements augmentent avec la taille des grosses particules. La présence des réarrangements est plus importante lorsque la porosité initiale du lit est élevée. La dernière partie de la thèse étudie l'injection de poudres de bois avec une vis sans fin à échelle pilote. Les essais sont réalisés en grande partie à pression atmosphérique. L'influence de la morphologie des particules sur l'énergie requise par la vis d'injection et sur le débit massique de poudre est mise en évidence. L'injection de particules grossières et allongées nécessite plus d'énergie que celle de particules fines et sphériques. Le remplissage de la vis est d'autant plus important que la distribution granulométrique est étendue. La longueur de cohésion est le rapport des forces de cohésion sur la force de pesanteur. Cet indicateur prédit correctement la capacité des poudres étudiées à s'écouler sans former de voûte. Enfin, une poudre de bois torréfiée est gazéifiée avec succès dans un réacteur à flux entraîné pilote sous une pression de 7 bars, à un débit d'entrée de 15 kg/h.
Download or read book Le bois written by Sid-Ahmed Rezzoug and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Le bois written by Sid-Ahmed Rezzoug and published by . This book was released on 2006 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Etude du s chage du bois en vue d une utilisation nerg tique written by Bunyat Ayarungsaritkul and published by . This book was released on 1985 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: ETUDE EXPERIMENTALE DU COMPORTEMENT AU SECHAGE DE PLAQUETTES DE BOIS (CINETIQUE, INFLUENCE DES CONDITIONS OPERATOIRES ET DE LA NATURE DES LOIS). ESSAI D'UN SECHOIR CONTINU A RECYCLAGE D'AIR CHAUD, A CO-COURANT ET A CONTRE COURANT
Download or read book Terra 2008 written by Leslie Rainer and published by Getty Publications. This book was released on 2011-06-14 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthen architecture constitutes one of the most diverse forms of cultural heritage and one of the most challenging to preserve. It dates from all periods and is found on all continents but is particularly prevalent in Africa, where it has been a building tradition for centuries. Sites range from ancestral cities in Mali to the palaces of Abomey in Benin, from monuments and mosques in Iran and Buddhist temples on the Silk Road to Spanish missions in California. This volume's sixty-four papers address such themes as earthen architecture in Mali, the conservation of living sites, local knowledge systems and intangible aspects, seismic and other natural forces, the conservation and management of archaeological sites, research advances, and training.
Download or read book Faecal Sludge Management written by Linda Strande and published by IWA Publishing. This book was released on 2014-08-15 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is estimated that literally billions of residents in urban and peri-urban areas of Africa, Asia, and Latin America are served by onsite sanitation systems (e.g. various types of latrines and septic tanks). Until recently, the management of faecal sludge from these onsite systems has been grossly neglected, partially as a result of them being considered temporary solutions until sewer-based systems could be implemented. However, the perception of onsite or decentralized sanitation technologies for urban areas is gradually changing, and is increasingly being considered as long-term, sustainable options in urban areas, especially in low- and middle-income countries that lack sewer infrastructures. This is the first book dedicated to faecal sludge management. It compiles the current state of knowledge of the rapidly evolving field of faecal sludge management, and presents an integrated approach that includes technology, management, and planning based on Sandecs 20 years of experience in the field. Faecal Sludge Management: Systems Approach for Implementation and Operation addresses the organization of the entire faecal sludge management service chain, from the collection and transport of sludge, and the current state of knowledge of treatment options, to the final end use or disposal of treated sludge. The book also presents important factors to consider when evaluating and upscaling new treatment technology options. The book is designed for undergraduate and graduate students, and engineers and practitioners in the field who have some basic knowledge of environmental and/or wastewater engineering.
Download or read book Basic Technics in Ecological Farming Techniques de Base en Agriculture Biologique Grunds tzliche Verfahren der kologischen Landwirtschaft Le Maintien de la Fertilit des Sols The Maintenance of Soil Fertility Die Erhaltung der Bodenfruchtbarkeit written by Stuart Hill and published by Birkhäuser. This book was released on 2013-12-14 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book How to Design Wastewater Systems for Local Conditions in Developing Countries written by David M. Robbins and published by IWA Publishing. This book was released on 2014-03-15 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a practical handbook providing a step-by-step approach to the techniques used for characterizing wastewater sources and investigating sites where collection, treatment and reuse/disposal technologies will be installed. It is intended to help enable local implementation of on-site and decentralized wastewater management system (DWMS)for wide scale use in development settings. How to Design Wastewater Systems for Local Conditions in Developing Countries helps local service providers and regulatory officials make informed decisions through the use of tools, checklists and case studies. It includes a link to a web based community of on-site and decentralized wastewater professionals, which contains related tools and case studies. This handbook serves as a reference for training classes, certification programs, and higher education programs in civil and sanitary engineering. There is an increasing interest on the part of local government officials and private sector service providers to implement wastewater treatment systems to solve sanitation problems. The model presented in this handbook promotes activities that first generate data related to source and site conditions that represent critical inputs, and then applies this information to the technology selection process. Matching the most appropriate technologies to the specific needs of the wastewater project is the key that leads to long term sustainability. How to Design Wastewater Systems for Local Conditions in Developing Countries is an invaluable resource for public sector decision makers and private sector service providers in developing countries. It is also a useful text for students at engineering colleges in developing countries interested in taking a class that teaches the methods of decentralized wastewater management system (DWMS) development.
Download or read book Compendium of Sanitation Systems and Technologies written by Elizabeth Tilley and published by . This book was released on 2014 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Boundaries of the West African Craton written by Nasser Ennih and published by Geological Society of London. This book was released on 2008 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Science of metals written by Zay Jeffries and published by . This book was released on 1924 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Origins of Comics written by Thierry Smolderen and published by Univ. Press of Mississippi. This book was released on 2014-03-25 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: In The Origins of Comics: From William Hogarth to Winsor McCay, Thierry Smolderen presents a cultural landscape whose narrative differs in many ways from those presented by other historians of the comic strip. Rather than beginning his inquiry with the popularly accepted "sequential art" definition of the comic strip, Smolderen instead wishes to engage with the historical dimensions that inform that definition. His goal is to understand the processes that led to the twentieth-century comic strip, the highly recognizable species of picture stories that he sees crystallizing around 1900 in the United States. Featuring close readings of the picture stories, caricatures, and humoristic illustrations of William Hogarth, Rodolphe Töpffer, Gustave Doré, and their many contemporaries, Smolderen establishes how these artists were immersed in a very old visual culture in which images—satirical images in particular—were deciphered in a way that was often described as hieroglyphical. Across eight chapters, he acutely points out how the effect of the printing press and the mass advent of audiovisual technologies (photography, audio recording, and cinema) at the end of the nineteenth century led to a new twentieth-century visual culture. In tracing this evolution, Smolderen distinguishes himself from other comics historians by following a methodology that explains the present state of the form of comics on the basis of its history, rather than presenting the history of the form on the basis of its present state. This study remaps the history of this influential art form.
Download or read book Creating Futures written by Michel Godet and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Population Environment and Development written by UN. Population Division and published by United Nations Publications. This book was released on 2001 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The general trends of rapid population growth, sustained but uneven economic improvement, and environmental degradation, are well known. Population and development policies are vital components of action needed to ensure sustainable development and to safeguard the environment. The topics investigated in this report include: the evolution of population and the environment at major UN conferences; trends in population, environment and development; government views; health, mortality, fertility and the environment; urbanization.
Download or read book Mining Society and a Sustainable World written by Jeremy Richards and published by Springer Science & Business Media. This book was released on 2009-09-18 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book of peer-reviewed, edited papers that examines the minerals industry in relation to sustainable development. The book takes a proactive, positivist, and solution-oriented approach, while not shying away from the fundamental problems.
Download or read book Agrimonde Scenarios and Challenges for Feeding the World in 2050 written by Sandrine Paillard and published by Springer. This book was released on 2016-09-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: How will the world be able to feed close to 9 billion people in 2050 and still maintain the ecosystems? In this perspective, INRA and CIRAD launched the initiative, in 2006, to develop a foresight project for analysing issues pertaining to the world's food and agricultural systems on the 2050 timeline. This book provides a synthetic presentation of the main conclusions that this foresight project has yielded. First, it recapitulates the main statistical references for the period 1961 to 2003, before going on to describe the Agribiom simulation tool used to calculate food biomass resource use balances. Two scenarios on the 2050 timeline are then considered: Agrimonde GO is a trend-based scenario that bets on economic growth to feed the world, in a context where environmental protection is not a priority; in contrast, the idea in Agrimonde 1 is to feed the world while preserving its ecosystems.
Download or read book Medical Botany written by and published by . This book was released on 1821 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
