20 resultados para RAW MATERIALS
em Universidad Politécnica de Madrid
Resumo:
Biochar can provide multiple benefits in the ecosystem. However, the presence of phytotoxic compounds in some biochars is an important concern that needs to be addressed and that depends on the raw material and the pyrolysis conditions used in biochar production. For example, sewage sludge biochars can have elevated heavy metal con- tents as they were present in the feedstock and were enriched during pyrolysis. Also during carbonization, some phytotoxic compounds such as polycyclic aromatic hydrocarbons (PAHs), polyphenols or volatile organic com- pounds (VOCs) could be formed representing a risk of contamination to soils and crops. In this work we report the results from seed germination and plant development for three biochars prepared from wood, paper sludge plus wheat husks and sewage sludge. Five higher plant species (cress, lentils, cucumber, tomato and lettuce) were studied. Biochar from wood shows seed inhibition in several species and the paper sludge biochar on lettuce. For the rest, the effect on seed germination was positive. No inhibition of root growth was detected, but in some cases leaves and stems growth were inhibited. Our results are significant in terms of advancing or current understanding on the impacts of biochar on vegetative growth and linking those effects to biochar properties.
Resumo:
The construction industry, one of the most important ones in the development of a country, generates unavoidable impacts on the environment. The social demand towards greater respect for the environment is a high and general outcry. Therefore, the construction industry needs to reduce the impact it produces. Proper waste management is not enough; we must take a further step in environmental management, where new measures need to be introduced for the prevention at source, such as good practices to promote recycling. Following the amendment of the legal frame applicable to Construction and Demolition Waste (C&D waste), important developments have been incorporated in European and International laws, aiming to promote the culture of reusing and recycling. This change of mindset, that is progressively taking place in society, is allowing for the consideration of C&D waste no longer as an unusable waste, but as a reusable material. The main objective of the work presented in this paper is to enhance C&D waste management systems through the development of preventive measures during the construction process. These measures concern all the agents intervening in the construction process as only the personal implication of all of them can ensure an efficient management of the C&D waste generated. Finally, a model based on preventive measures achieves organizational cohesion between the different stages of the construction process, as well as promoting the conservation of raw materials through the use and waste minimization. All of these in order to achieve a C&D waste management system, whose primary goal is zero waste generation
Resumo:
Agricultural wastes are a source of renewable raw materials (RRM), with structures that can be tailored for the use envisaged. Here, they have proved to be good replacement candidates for use as biomaterials for the growth of osteoblasts in bone replacement therapies. Their preparation is more cost effective than that of materials presently in use with the added bonus of converting a low-cost waste into a value-added product. Due to their origin these solids are ecomaterials. In this study, several techniques, including X-ray diffraction (XRD), chemical analysis, mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and bioassays, were used to compare the biocompatibility and cell growth of scaffolds produced from beer bagasse, a waste material from beer production, with a control sample used in bone and dental regenerative processes.
Resumo:
Supply chain management works to bring the supplier, the distributor, and the customer into one cohesive process. The Supply Chain Council defined supply chain as ‘Supply Chain: The flow and transformation of raw materials into products from suppliers through production and distribution facilities to the ultimate consumer., and then Sunil Chopra and Meindl, (2001) have define Supply chain management as ‘Supply Chain Management involves the flows between and among stages in a supply chain to maximize total profitability.’ After 1950, supply chain management got a boost with the production and manufacturing sector getting highest attention. The inventory became the responsibility of the marketing, accounting and production areas. Order processing was part of accounting and sales. Supply chain management became one of the most powerful engines of business transformation. It is the one area where operational efficiency can be gained. It reduces organizations costs and enhances customer service. With the liberalization of world trade, globalization, and emergence of the new markets, many organizations have customers and competitions throughout the world, either directly or indirectly. Business communities are aware that global competitiveness is the key to the success of a business. Competitiveness is ability to produce, distribute and provide products and services for the open market in competition with others. The supply chain, a critical link between supplier, producer and customer is emerged now as an essential business process and a strategic lever, potential value contributor a differentiator for the success of any business. Supply chain management is the management of all internal and external processes or functions to satisfy a customer’s order (from raw materials through conversion and manufacture through logistics delivery.). Goods-either in raw form or processed, whole sale or retailed distribution, business or technology services, in everyday life- in the business or household- directly or indirectly supply chain is ubiquitously associated in expanding socio-economic development. Supply chain growth competitive performance and supporting strong growth impulse at micro as well as micro economic levels. Keeping the India vision at the core of the objective, the role of supply chain is to take up social economic challenges, improve competitive advantages, develop strategies, built capabilities, enhance value propositions, adapt right technology, collaborate with stakeholders and deliver environmentally sustainable outcomes with minimum resources.
Resumo:
El gran desarrollo industrial y demográfico de las últimas décadas ha dado lugar a un consumo crecientemente insostenible de energía y materias primas, que influye negativamente en el ambiente por la gran cantidad de contaminantes generados. Entre las emisiones tienen gran importancia los compuestos orgánicos volátiles (COV), y entre ellos los compuestos halogenados como el tricloroetileno, debido a su elevada toxicidad y resistencia a la degradación. Las tecnologías generalmente empleadas para la degradación de estos compuestos presentan inconvenientes derivados de la generación de productos tóxicos intermedios o su elevado coste. Dentro de los procesos avanzados de oxidación (Advanced Oxidation Processes AOP), la fotocatálisis resulta una técnica atractiva e innovadora de interés creciente en su aplicación para la eliminación de multitud de compuestos orgánicos e inorgánicos, y se ha revelado como una tecnología efectiva en la eliminación de compuestos orgánicos volátiles clorados como el tricloroetileno. Además, al poder aprovechar la luz solar como fuente de radiación UV permite una reducción significativa de costes energéticos y de operación. Los semiconductores más adecuados para su empleo como fotocatalizadores con aprovechamiento de la luz solar son aquellos que tienen una banda de energía comparable a la de los fotones de luz visible o, en su defecto, de luz ultravioleta A (Eg < 3,5 eV), siendo el más empleado el dióxido de titanio (TiO2). El objetivo principal de este trabajo es el estudio de polímeros orgánicos comerciales como soporte para el TiO2 en fotocatálisis heterogénea y su ensayo para la eliminación de tricloroetileno en aire. Para ello, se han evaluado sus propiedades ópticas y su resistencia a la fotodegradación, y se ha optimizado la fijación del fotocatalizador para conseguir un recubrimiento homogéneo, duradero y con elevada actividad fotocatalítica en diversas condiciones de operación. Los materiales plásticos ensayados fueron el polietileno (PE), copolímero de etil vinil acetato con distintos aditivos (EVA, EVA-H y EVA-SH), polipropileno (PP), polimetil (metacrilato) fabricado en colada y extrusión (PMMA-C y PMMA-E), policarbonato compacto y celular (PC-C y PC-Ce), polivinilo rígido y flexible (PVC-R y PVC-F), poliestireno (PS) y poliésteres (PET y PETG). En base a sus propiedades ópticas se seleccionaron el PP, PS, PMMA-C, EVA-SH y PVC-R, los cuales mostraron un valor de transmitancia superior al 80% en el entorno de la región estudiada (λ=365nm). Para la síntesis del fotocatalizador se empleó la tecnología sol-gel y la impregnación multicapa de los polímeros seleccionados por el método de dip-coating con secado intermedio a temperaturas moderadas. Con el fin de evaluar el envejecimiento de los polímeros bajo la radiación UV, y el efecto sobre éste del recubrimiento fotoactivo, se realizó un estudio en una cámara de exposición a la luz solar durante 150 días, evaluándose la resistencia química y la resistencia mecánica. Los resultados de espectroscopía infrarroja y del test de tracción tras el envejecimiento revelaron una mayor resistencia del PMMA y una degradación mayor en el PS, PVC-R y EVA SH, con una apreciable pérdida del recubrimiento en todos los polímeros. Los fotocatalizadores preparados sobre soportes sin tratamiento y con tres capas de óxido de titanio mostraron mejores resultados de actividad con PMMA-C, PET y PS, con buenos resultados de mineralización. Para conseguir una mayor y mejor fijación de la película al soporte se realizaron tratamientos químicos abrasivos con H2SO4 y NaOH y tratamientos de funcionalización superficial por tecnología de plasma a presión atmosférica (APP) y a baja presión (LPP). Con los tratamientos de plasma se consiguió una excelente mojabilidad de los soportes, que dio lugar a una distribución uniforme y más abundante del fotocatalizador, mientras que con los tratamientos químicos no se obtuvo una mejora significativa. Asimismo, se prepararon fotocatalizadores con una capa previa de dióxido de silicio con la intervención de surfactantes (PDDA-SiO2-3TiO2 y SiO2FC-3TiO2), consiguiéndose buenas propiedades de la película en todos los casos. Los mejores resultados de actividad con tratamiento LPP y tres capas de TiO2 se lograron con PMMA-C (91% de conversión a 30 ppm de TCE y caudal 200 ml·min-1) mejorando significativamente también la actividad fotocatalítica en PVC-R y PS. Sin embargo, el material más activo de todos los ensayados fue el PMMA-C con el recubrimiento SiO2FC-3TiO2, logrando el mejor grado de mineralización, del 45%, y una velocidad de 1,89 x 10-6 mol· m-2 · s-1, que dio lugar a la eliminación del 100 % del tricloroetileno en las condiciones anteriormente descritas. A modo comparativo se realizaron ensayos de actividad con otro contaminante orgánico tipo, el formaldehído, cuya degradación fotocatalítica fue también excelente (100% de conversión y 80% de mineralización con 24 ppm de HCHO en un caudal de aire seco de 200 ml·min-1). Los buenos resultados de actividad obtenidos confirman las enormes posibilidades que ofrecen los polímeros transparentes en el UV-A como soportes del dióxido de titanio para la eliminación fotocatalítica de contaminantes en aire. ABSTRACT The great industrial and demographic development of recent decades has led to an unsustainable increase of energy and raw materials consumption that negatively affects the environment due to the large amount of waste and pollutants generated. Between emissions generated organic compounds (VOCs), specially the halogenated ones such as trichloroethylene, are particularly important due to its high toxicity and resistance to degradation. The technologies generally used for the degradation of these compounds have serious inconveniences due to the generation of toxic intermediates turn creating the problem of disposal besides the high cost. Among the advanced oxidation processes (AOP), photocatalysis is an attractive and innovative technique with growing interest in its application for the removal of many organic and inorganic compounds, and has emerged as an effective technology in eliminating chlorinated organic compounds such as trichloroethylene. In addition, as it allows the use of sunlight as a source of UV radiation there is a significant reduction of energy costs and operation. Semiconductors suitable to be used as photocatalyst activated by sunlight are those having an energy band comparable to that of the visible or UV-A light (Eg <3,5 eV), being titanium dioxide (TiO2), the most widely used. The main objective of this study is the test of commercial organic polymers as supports for TiO2 to be applied in heterogeneous photocatalysis and its assay for removing trichloroethylene in air. To accomplish that, its optical properties and resistance to photooxidation have been evaluated, and different operating conditions have been tested in order to optimize the fixation of the photocatalyst to obtain a homogeneous coating, with durable and high photocatalytic activity. The plastic materials tested were: polyethylene (PE), ethyl vinyl acetace copolymers with different additives (EVA, EVA-H and EVA -SH), polypropylene (PP), poly methyl (methacrylate) manufactured by sheet moulding and extrusion (PMMA-C and PMMA-E), compact and cellular polycarbonates (PC-C PC-Ce), rigid and flexible polyvinyl chloride (PVC-R and PVC-F), polystyrene (PS) and polyesters (PET and PETG). On the basis of their optical properties PP, PS, PMMA-C, EVA-SH and PVC-R were selected, as they showed a transmittance value greater than 80% in the range of the studied region (λ = 365nm). For the synthesis of the photocatalyst sol-gel technology was employed with multilayers impregnation of the polymers selected by dip-coating, with intermediate TiO2 drying at moderate temperatures. To evaluate the polymers aging due to UV radiation, and the effect of photoactive coating thereon, a study in an sunlight exposure chamber for 150 days was performed, evaluating the chemical resistance and the mechanical strength. The results of infrared spectroscopy and tensile stress test after aging showed the PMMA is the most resistant sample, but a greater degradation in PS, PVC-R and EVA SH, with a visible loss of the coating in all the polymers tested. The photocatalysts prepared on the untreated substrates with three layers of TiO2 showed better activity results when PMMA-C, PET and PS where used. To achieve greater and better fixation of the film to the support, chemical abrasive treatments, with H2SO4 and NaOH, as well as surface functionalization treatments with atmospheric pressure plasma (APP) and low pressure plasma (LPP) technologies were performed. The plasma treatment showed the best results, with an excellent wettability of the substrates that lead to a better and uniform distribution of the photocatalyst compared to the chemical treatments tested, in which no significant improvement was obtained. Also photocatalysts were prepared with the a silicon dioxide previous layer with the help of surfactants (SiO2- 3TiO2 PDDA-and-3TiO2 SiO2FC), obtaining good properties of the film in all cases. The best activity results for LPP-treated samples with three layers of TiO2 were achieved with PMMA-C (91% conversion, in conditions of 30 ppm of TCE and 200 ml·min-1 air flow rate), with a significant improvement of the photocatalytic activity in PVC-R and PS samples too. However, among all the materials assayed, PMMA-C with SiO2FC-3TiO2 coating was the most active one, achieving the highest mineralization grade (45%) and a reaction rate of 1,89 x 10-6 mol· m-2 · s-1, with total trichloroethylene elimination in the same conditions. As a comparative assay, an activity test was also performed with another typical organic contaminant, formaldehyde, also with good results (100% conversion with 24 ppm of HCHO and 200 ml·min-1 gas flow rate). The good activity results obtained in this study confirm the great potential of organic polymers which are transparent in the UV-A as supports for titanium dioxide for photocatalytic removal of air organic pollutants.
Resumo:
A sustainable manufacturing process must rely on an also sustainable raw materials and energy supply. This paper is intended to show the results of the studies developed on sustainable business models for the minerals industry as a fundamental previous part of a sustainable manufacturing process. As it has happened in other economic activities, the mining and minerals industry has come under tremendous pressure to improve its social, developmental, and environmental performance. Mining, refining, and the use and disposal of minerals have in some instances led to significant local environmental and social damage. Nowadays, like in other parts of the corporate world, companies are more routinely expected to perform to ever higher standards of behavior, going well beyond achieving the best rate of return for shareholders. They are also increasingly being asked to be more transparent and subject to third-party audit or review, especially in environmental aspects. In terms of environment, there are three inter-related areas where innovation and new business models can make the biggest difference: carbon, water and biodiversity. The focus in these three areas is for two reasons. First, the industrial and energetic minerals industry has significant footprints in each of these areas. Second, these three areas are where the potential environmental impacts go beyond local stakeholders and communities, and can even have global impacts, like in the case of carbon. So prioritizing efforts in these areas will ultimately be a strategic differentiator as the industry businesses continues to grow. Over the next forty years, world?s population is predicted to rise from 6.300 million to 9.500 million people. This will mean a huge demand of natural resources. Indeed, consumption rates are such that current demand for raw materials will probably soon exceed the planet?s capacity. As awareness of the actual situation grows, the public is demanding goods and services that are even more environmentally sustainable. This means that massive efforts are required to reduce the amount of materials we use, including freshwater, minerals and oil, biodiversity, and marine resources. It?s clear that business as usual is no longer possible. Today, companies face not only the economic fallout of the financial crisis; they face the substantial challenge of transitioning to a low-carbon economy that is constrained by dwindling natural resources easily accessible. Innovative business models offer pioneering companies an early start toward the future. They can signal to consumers how to make sustainable choices and provide reward for both the consumer and the shareholder. Climate change and carbon remain major risk discontinuities that we need to better understand and deal with. In the absence of a global carbon solution, the principal objective of any individual country should be to reduce its global carbon emissions by encouraging conservation. The mineral industry internal response is to continue to focus on reducing the energy intensity of our existing operations through energy efficiency and the progressive introduction of new technology. Planning of the new projects must ensure that their energy footprint is minimal from the start. These actions will increase the long term resilience of the business to uncertain energy and carbon markets. This focus, combined with a strong demand for skills in this strategic area for the future requires an appropriate change in initial and continuing training of engineers and technicians and their awareness of the issue of eco-design. It will also need the development of measurement tools for consistent comparisons between companies and the assessments integration of the carbon footprint of mining equipments and services in a comprehensive impact study on the sustainable development of the Economy.
Resumo:
Nowadays, processing Industry Sector is going through a series of changes, including right management and reduction of environmental affections. Any productive process which looks for sustainable management is incomplete if Cycle of Life of mineral resources sustainability is not taken into account. Raw materials for manufacturing are provided by mineral resources extraction processes, such as copper, aluminum, iron, gold, silver, silicon, titanium? Those elements are necessary for Mankind development and are obtained from the Earth through mineral extractive processes. Mineral extraction processes are operations which must take care about the environmental consequences. Extraction of huge volumes of rock for their transformation into raw materials for industry must be optimized to reduce ecological cost of the final product as l was possible. Reducing the ecological balance on a global scale has no sense to design an efficient manufacturing in secondary industry (transformation), if in first steps of the supply chain (extraction) impact exceeds the savings of resources in successive phases. Mining operations size suggests that it is an environmental aggressive activity, but precisely because of its great impact must be the first element to be considered. That idea implies that a new concept born: Reduce economical and environmental cost This work aims to make a reflection on the parameters that can be modified to reduce the energy cost of the process without an increasing in operational costs and always ensuring the same production capacity. That means minimize economic and environmental cost at same time. An efficient design of mining operation which has taken into account that idea does not implies an increasing of the operating cost. To get this objective is necessary to think in global operation view to make that all departments involved have common guidelines which make you think in the optimization of global energy costs. Sometimes a single operational cost must be increased to reduce global cost. This work makes a review through different design parameters of surface mining setting some key performance indicators (KPIs) which are estimated from an efficient point of view. Those KPIs can be included by HQE Policies as global indicators. The new concept developed is that a new criteria has to be applied in company policies: improve management, improving OPERATIONAL efficiency. That means, that is better to use current resources properly (machinery, equipment,?) than to replace them with new things but not used correctly. As a conclusion, through an efficient management of current technologies in each extractive operation an important reduction of the energy can be achieved looking at downstream in the process. That implies a lower energetic cost in the whole cycle of life in manufactured product.
Resumo:
El objetivo del presente trabajo es determinar la localización óptima de una planta de producción de 30.000 m3/año de bioetanol a partir de tubérculos de pataca (Helianthus tuberosus L.) cultivada en regadío, en tierras de barbecho de la Cuenca Hidrográfica del Duero (CH Duero). Inicialmente se elaboró, a partir de datos bibliográficos, un modelo de producción de pataca en base a una ecuación de regresión que relaciona datos experimentales de rendimientos de variedades tardías con variables agroclimáticas. Así se obtuvo una función de producción basada en la cantidad de agua disponible (precipitación efectiva + dosis de riego) y en la radiación global acumulada en el periodo brotación‐senescencia del cultivo. A continuación se estima la superficie potencial de cultivo de pataca en la CH Duero a partir de la superficie arable en regadío cartografiada por el Sistema de Ocupación del Suelo (SIOSE), a la cual se le aplican, en base a los requerimientos del cultivo, unas restricciones climáticas, edafológicas, topográficas y logísticas mediante el uso de Sistemas de Información Geográfica (SIG). La proporción de superficie de regadío restringida se cuantifica a escala municipal con el fin de calcular la superficie de barbecho en regadío apta para el cultivo de pataca. A partir de las bases de datos georreferenciadas de precipitación, radiación global, y la dotación de agua para el riego de cultivos no específicos establecida en el Plan Hidrológico de la Cuenca del Duero a escala comarcal, se estimó la producción potencial de tubérculos de pataca sobre la superficie de barbecho de regadío según el modelo de producción elaborado. Así, en las 53.360 ha de barbecho en regadío aptas para el cultivo de pataca se podrían producir 3,8 Mt de tubérculos al año (80 % de humedad) (761.156 t ms/año) de los que se podría obtener 304.462 m3/año de bioetanol, considerando un rendimiento en la transformación de 12,5 kg mf/l de etanol. Se estiman los costes de las labores de cultivo de pataca así como los costes de la logística de suministro a una planta de transformación considerando una distancia media de transporte de 25 km, en base a las hojas de cálculo de utilización de aperos y maquinaria agrícola oficiales del Ministerio de Agricultura, Alimentación y Medio Ambiente (MAGRAMA). Considerando el balance de costes asociados a la producción de bioetanol (costes de transformación, distribución y transporte del producto, costes estructurales de la planta, ahorro de costes por la utilización de las vinazas generadas en el proceso como fertilizante y un beneficio industrial), se ha estimado que el coste de producción de bioetanol a partir de tubérculos de pataca asciende a 61,03 c€/l. Se calculan los beneficios fiscales para el Estado por el cultivo de 5.522 ha de pataca que suministren la materia prima necesaria para una planta de bioetanol de 30.000 m3/año, en concepto de cotizaciones a la Seguridad Social de los trabajadores, impuestos sobre el valor añadido de los productos consumidos, impuesto sobre sociedades y ahorro de las prestaciones por desempleo. Se obtuvieron unos beneficios fiscales de 10,25 c€ por litro de bioetanol producido. El coste de producción de bioetanol depende del rendimiento de tubérculos por hectárea y de la distancia de transporte desde las zonas de producción de la materia prima hasta la planta. Se calculó la distancia máxima de transporte para que el precio de coste del bioetanol producido sea competitivo con el precio de mercado del bioetanol. Como resultado se determinó que el precio del bioetanol (incluido un beneficio industrial del 15%) de la planta sería igual o inferior al precio de venta en el mercado (66,35 c€/l) con una distancia máxima de transporte de 25 km y un rendimiento mínimo del cultivo de 60,1 t mf/ha. Una vez conocido el área de influencia de la planta según la distancia de transporte máxima, se determinó la localización óptima de la planta de producción de bioetanol mediante un proceso de ubicación‐asignación realizado con SIG. Para ello se analizan los puntos candidatos a la ubicación de la planta según el cumplimiento de unos requerimientos técnicos establecidos (distancia a fuentes de suministro eléctrico y de recursos hídricos, distancia a estaciones de ferrocarril, distancia a núcleos urbanos y existencia de Espacios Naturales Protegidos) que minimizan la distancia de transporte maximizando la cantidad de biomasa disponible según la producción potencial estimada anteriormente. Por último, la superficie destinada al cultivo de pataca en el área de influencia de la planta se determina en base a un patrón de distribución del cultivo alrededor de una agroindustria. Dicho patrón se ha obtenido a partir del análisis del grado de ocupación del cultivo de la remolacha en función de la distancia de transporte a la planta azucarera de Miranda de Ebro (Burgos). El patrón resultante muestra que la relación entre el grado de ocupación del suelo por el cultivo y la distancia de transporte a la planta siguen una ecuación logística. La localización óptima que se ha obtenido mediante la metodología descrita se ubica en el municipio leonés de El Burgo Ranero, donde la producción potencial de tubérculos de pataca en la superficie de barbecho situada en un radio de acción de 25 km es de 375.665 t mf/año, superando las 375.000 t mf requeridas anualmente por la planta de bioetanol. ABSTRACT Jerusalem artichoke (Helianthus tuberosus L.) is a harsh crop with a high potential for biomass production. Its main use is related to bioethanol production from the carbohydrates, inulin mainly, accumulated in its tubers at the end of the crop cycle. The aerial biomass could be used as solid biofuel to provide energy to the bioethanol production process. Therefore, Jerusalem artichoke is a promising crop as feedstock for biofuel production in order to achieve the biofuels consumption objectives established by the Government of Spain (PER 2011‐2020 and RDL 4/2013) and the European Union (Directive 2009/28/EC). This work aims at the determination of the optimal location for a 30,000 m3/year bioethanol production plant from Jerusalem artichoke tubers in the Duero river basin. With this purpose, a crop production model was developed by means of a regression equation that relates experimental yield data of late Jerusalem artichoke varieties with pedo‐climatic parameters from a bibliographic data matrix. The resulting crop production model was based on the crop water availability (including effective rainfall and irrigation water supplied) and on global radiation accumulated in the crop emergence‐senescence period. The crop potential cultivation area for Jerusalem artichoke in the Duero basin was estimated using the georeferenced irrigated arable land from the “Sistema de Ocupación del Suelo” (SIOSE) of Spain. Climatic, soil, slope and logistic restrictions were considered by means of Geographic Information Systems (GIS). The limited potential growing area was then applied to a municipality scale in order to calculate the amount of fallow land suitable for Jerusalem artichoke production. Rainfall and global radiation georeferenced layers as well as data of irrigation water supply for crop production (established within the Duero Hydrologic Plan) were use to estimate the potential production of Jerusalem artichoke tubers in the suitable fallow land according to the crop production model. As a result of this estimation, there are 53,360 ha of fallow land suitable for Jerusalem artichoke production in the Duero basin, where 3.8 M t fm/year could be produced. Considering a bioethanol processing yield of 12.5 kg mf per liter of bioethanol, the above mentioned tuber potential production could be processed in 304,462 m3/year of bioethanol. The Jerusalem crop production costs and the logistic supply costs (considering an average transport distance of 25 km) were estimated according to official agricultural machinery cost calculation sheets of the Minister of Agriculture of Spain (MAGRAMA). The bioethanol production cost from Jerusalem artichoke tubers was calculated considering bioethanol processing, transport and structural costs, industrial profits as well as plant cost savings from the use of vinasses as fertilizer. The resulting bioetanol production cost from Jerusalem artichoke tubers was 61.03 c€/l. Additionally, revenues for the state coffers regarding Social Security contributions, added value taxes of consumed raw materials, corporation tax and unemployment benefit savings due to the cultivation of 5,522 ha of Jerusalem artichoke for the 30.000 m3/year bioethanol plant supply were calculated. The calculated revenues amounted to 10.25 c€/l. Bioethanol production cost and consequently the bioethanol plant economic viability are strongly related to the crop yield as well as to road transport distance from feedstock production areas to the processing plant. The previously estimated bioethanol production cost was compared to the bioethanol market price in order to determine the maximum supply transport distance and the minimum crop yield to reach the bioethanol plant economic viability. The results showed that the proposed plant would be economically viable at a maximum transport distance of 25 km and at a crop yield not less than 60.1 t fm/ha. By means of a GIS location‐allocation analysis, the optimal bioethanol plant location was determined. Suitable candidates were detected according to several plant technical requirements (distance to power and water supply sources, distance to freight station, and distance to urban areas and to Natural Protected Areas). The optimal bioethanol plant location must minimize the supply transport distance whereas it maximizes the amount of available biomass according to the previously estimated biomass potential production. Lastly, the agricultural area around the bioethanol plant finally dedicated to Jerusalem artichoke cultivation was planned according to a crop distribution model. The crop distribution model was established from the analysis of the relation between the sugar beet (Beta vulgaris L.) cropping area and the road transport distance from the sugar processing plant of Miranda de Ebro (Burgos, North of Spain). The optimal location was situated in the municipality of ‘El Burgo Ranero’ in the province of León. The potential production of Jerusalem artichoke tubers in the fallow land within 25 km distance from the plant location was 375,665 t fm/year, which exceeds the amount of biomass yearly required by the bioethanol plant.
Resumo:
In the current uncertain context that affects both the world economy and the energy sector, with the rapid increase in the prices of oil and gas and the very unstable political situation that affects some of the largest raw materials’ producers, there is a need for developing efficient and powerful quantitative tools that allow to model and forecast fossil fuel prices, CO2 emission allowances prices as well as electricity prices. This will improve decision making for all the agents involved in energy issues. Although there are papers focused on modelling fossil fuel prices, CO2 prices and electricity prices, the literature is scarce on attempts to consider all of them together. This paper focuses on both building a multivariate model for the aforementioned prices and comparing its results with those of univariate ones, in terms of prediction accuracy (univariate and multivariate models are compared for a large span of days, all in the first 4 months in 2011) as well as extracting common features in the volatilities of the prices of all these relevant magnitudes. The common features in volatility are extracted by means of a conditionally heteroskedastic dynamic factor model which allows to solve the curse of dimensionality problem that commonly arises when estimating multivariate GARCH models. Additionally, the common volatility factors obtained are useful for improving the forecasting intervals and have a nice economical interpretation. Besides, the results obtained and methodology proposed can be useful as a starting point for risk management or portfolio optimization under uncertainty in the current context of energy markets.
Resumo:
Natural cement was patented in 1796 but it didn’t arrive in Spain until 1835. No one knows exactly where the production started in Spain, because it emerged independently at the same time in many places. Most of these outbreaks are concentrated in the north and northwest of Spain: Basque Country (Zumaya and Rezola) and Catalonia (San Celoní and San Juan de las Abadesas).Natural cement was extensively used to decorate historical buildings during the nineteenth and beginning of twentieth century in Madrid. It was the building material which realised the architects and builders dreams of mass-produced cast elements in a wide variety of styles. Its arrival replaced traditional materials that were used previously (lime, gypsum and hydraulic limes). However, its use was not extended in time, and soon it was replaced by the use of artificial Portland cements. During 20th century this building material disappeared from use. What remains is it’s memory, in thousands and thousands of “stone witnesses” in our cities. Final properties of the cement largely depend on raw materials used and its combustion temperature. However, it was characterised by an easily implementation on facade masonry, fast-setting (about 15 minutes), good resistance , an agreeable structural consistency and colour.This article aims to show first steps, evolution and decay of Natural Cement Industry in Spain and its application in Madrid.
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La producción y el transporte a obra de los productos cerámicos de carácter estructural suponen un importante consumo energético, que conlleva la emisión de gases de efecto invernadero a la atmósfera. El objetivo de la presente Tesis es demostrar la existencia de importantes diferencias en el valor del impacto ambiental asociado a los productos de cerámica estructural fabricados en España, y que estas diferencias podrían quedar cuantificadas y reflejadas mediante un análisis de Huella de Carbono y de la Energía Embebida. Se parte de la inexistencia en España, de base de datos contrastada y consensuada, que establezca las cargas medioambientales en función del tipo de producto cerámico a utilizar. Se realiza en la primera parte del estudio una revisión del estado actual de la Huella de Carbono y la Energía Embebida en el campo de los materiales de construcción, y más concretamente en el sector de la cerámica estructural, que sirve para acotar los límites del estudio y justificar el objeto de la Tesis. La investigación se acota a las etapas de producción y transporte a obra de los productos (estudio cuna a puerta con opciones), al considerar que son éstas, a priori, las que tienen una mayor incidencia en el comportamiento ambiental del producto. Siguiendo los pasos definidos en la normativa aplicable (definición del mapa de procesos – límites y alcance – inventario – cálculo y evaluación), se establece un método específico de identificación y cuantificación de las variables que determinan la Huella de Carbono y Energía Embebida de los productos cerámicos, en función de la tipología de producto. La información necesaria (inventario) se obtiene principalmente con recogida de datos “in situ” de fábricas de productos cerámicos, lo que garantiza que la información tratada en este estudio es de primer nivel. La información se complementa/contrasta con fuentes bibliográficas. Se determinan 6 variables con influencia global en el impacto ambiental, 44 variables principales y 39 secundarias, estableciendo las fórmulas de cálculo a partir de dichas variables. Los resultados de cálculo y evaluación determinan que, para unas mismas condiciones de fabricación, las diferencias entre productos cerámicos llegan hasta un 27% para la Huella de Carbono y un 35% para Energía Embebida. La relevancia que alcanza el impacto asociado al transporte del producto a obra puede llegar hasta un 40% del total. El método de cálculo y las fórmulas desarrolladas se integran en una hoja de cálculo, para el cálculo de Huella de Carbono y Energía Embebida de los productos cerámicos, que permite, a su vez, conocer la repercusión medioambiental que tiene la introducción de modificaciones o innovaciones en el proceso de producción o transporte a obra. Así mismo, el trabajo desarrollado ha servido para poner en relieve una serie de problemas y falta de información en el campo de la cerámica estructural y el medioambiente que pueden ser objeto de futuras líneas de investigación, tanto para el sector de la edificación como para la comunidad científica, pudiendo implementar la metodología desarrollada en otras investigaciones. Se considera que la investigación realizada y sus resultados suponen una aportación importante para conocer y reducir el impacto ambiental de los edificios, desde la perspectiva del ciclo de vida y considerando que el impacto ambiental de un edificio comienza desde el momento en que se extraen las materias primas para la fabricación de los materiales con los que se construyen los edificios. ABSTRACT The production and transport of structural ceramic products involves an important energy consumption, which leads to the emission of greenhouse gases into the atmosphere. The objective of the research is to demonstrate the existence of significant differences in the value of the environmental impact of structural ceramic products manufactured in Spain, and these differences could be quantified by the Carbon Footprint and Embodied Energy. It starts from the absence in Spain, of contrasted and agreed databases that establish the environmental loads depending on the type of ceramic product. In the first part of the study reviews the current state of the Carbon Footprint and Embedded Energy in the field of building materials, and more specifically in the field of structural ceramics, which serves to limit the scope of the study and justify the purpose of this Thesis. The Research is bounded to production and transportation stages of (cradle to gate with options), considering they are the stages that have a greater impact on the environmental performance of the product. Following the steps defined in applicable rules (definition of process map - boundaries and scope – inventory analysis- calculation and impact assessment), it sets a specific method for the identification and quantification of the variables that determine the Carbon Footprint and Embedded Energy of structural ceramic products, depending on the type of product. The information (inventory) is given mainly with a data collection in ceramic factories (and in a consultation with the manufactures of the products), ensuring that the information handled in this Thesis is a first rate data. It is established 6 variables with a global influence in the environmental impact, 44 primary and 39 secondary variables, establishing calculation formula from these variables. The results of calculation and assessment determined that, for same manufacturing conditions, the differences between ceramic products reach 27% for Carbon Footprint and 35% for Embodied Energy. The relevance that reaches the impact of transport can reach 40% of the total. The method of calculation and formulas developed are integrated into a simple calculation tool, excel base, to calculate the Carbon Footprint and Embodied Energy of structural ceramic products, which allows, know the environmental impact of changes or innovations in the production process or transport to work. The work also has served to find a problems and gaps in the field of structural ceramics and the environment that may well be the subject of future research, both for the building sector to the scientific community, implementing the methodology developed in other research. It is considered that the research and its results represent an important contribution to understand and reduce the environmental impact of buildings from the perspective of the life cycle, considering that the environmental impact of a building starts from the time that the raw materials are extracted for the manufacture of building materials.
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Uno de los retos a los que se enfrenta la humanidad es la demanda de una sociedad con casi cero residuos: la búsqueda de una economía más eficiente en el uso de los recursos teniendo en cuenta el cambio climático y un abastecimiento sostenible de materias primas que permitan satisfacer las necesidades de una población mundial cada vez mayor, dentro de los límites sostenibles de los recursos naturales del planeta. Abordar este desafío implica la recuperación y reciclaje de materiales para reducir consumos de materias primas y, para ello, debe promoverse la innovación en la prevención y gestión de residuos, como estrategia hacia un desarrollo urbano sostenible. Los envases y embalajes forman parte de la cultura actual, relacionándose con el grado de desarrollo de países y regiones; el sector de la construcción no es ajeno a la problemática y genera un importante volumen de embalajes en las obras que no se gestionan de forma adecuada. El modelo de gestión de Residuos de Construcción Demolición (RCD) actual es poco eficaz, ya que los vertederos siguen recibiendo grandes cantidades de residuos valorizables. La normativa ha conseguido minimizar las prácticas ilegales, pero se comprueba que la gestión actual de los RCD en obra deja en manos de las plantas de tratamiento la misión de separar los residuos según su naturaleza y los datos aportados por las distintas plantas no permiten afirmar el grado de alcance de dicho objetivo, ni el destino de los mismos. Los envases y embalajes son un tipo de residuos que por su naturaleza suponen una fuente de recursos valorizables y por ello están presentes en directivas y leyes, dirigidas fundamentalmente al sector de la alimentación. En el ámbito de la construcción, hasta la fecha, no se habían tratado de forma específica, motivo que justifica este trabajo. Esta Tesis Doctoral tiene como objetivo principal mejorar la gestión de residuos de embalajes procedentes de materiales de construcción. Para ello se estudia un importante conjunto de obras de edificación residencial colectiva de 1173 viviendas, análisis que llevará a conocer los patrones de producción de los Residuos de Envases y Embalajes en Construcción (REEC) e identificar los productos o materiales responsables de su generación. La monitorización realizada, permitirá diseñar estrategias específicas que minimicen la generación de estos residuos y optimicen su valorización. Se ha podido comprobar que el tratamiento particularizado de los REEC puede mejorar los resultados de la gestión del conjunto de RCD, debido a que, al no mezclarse, se elimina un importante agente contaminador de los residuos inertes. Las obras analizadas alcanzan un nivel de segregación in situ muy bajo, y los capítulos de cerramientos e instalaciones suman más del 50% del global de REEC. Particularizando en cada tipo de material, el cartón predomina en los trabajos de electricidad, el plástico en las particiones y la madera en fachadas. Se evalúa la opción del eco-‐rediseño para uno de los embalajes predominantes, y se identifican estrategias para minimizar su impacto. Se comprueba que el ahorro en la gestión de RCD en caso de impulsar la segregación in situ no es muy significativo en las obras estudiadas, si bien se demuestra que la viabilidad económica es el factor más importante para motivar a las empresas constructoras. Las Administraciones Públicas deberían incentivar la gestión responsable, estableciendo medidas de control en las plantas de tratamiento e implementando en sus obras medidas de gestión de RCD ejemplares para el mercado. Una adecuada planificación de la obra, y formación específica para el personal son medidas que facilitan la segregación in situ y mejoran los resultados. Los promotores, mediante su relación contractual con el resto de agentes, tienen la capacidad de establecer objetivos de reducción, planificación y gestión sostenible de los REEC. Por último, se propone un sistema de gestión de REEC, integrable dentro del Sistema de Gestión de la empresa constructora, que permite evitar que residuos valorizables tales como los envases y embalajes se envíen a vertedero, guiando al sector hacia un futuro más respetuoso, alineado con el desarrollo sostenible. ABSTRACT One of the challenges humanity faces is the demand of an almost zero waste society: the search for a more efficient economy in the use of resources, taking into account climate change and a sustainable supply of raw materials, that meet the needs of an increasing world population within the sustainable limits of the planet's natural resources. Addressing this challenge involves the recovery and recycling of materials to reduce consumption of raw materials, so innovation must therefore be promoted in the prevention and management of waste, as a strategy towards a sustainable urban development. Packaging is part of our current culture and is related to the degree of development of countries and regions; the construction sector is no stranger to this problem and generates a significant amount of packaging waste in the site works, which nowadays is not managed properly. The current Construction Demolition Waste (CDW) management model is ineffective, since landfills continue to receive large amounts of recoverable waste. The legislation has managed to minimize illegal practices, but it has been observed that the current management of CDW in the analysed works leaves the mission of separating waste according to their nature to the plants, and data provided by the latter does not allow for checking the scope of this objective, nor the destiny of the waste. Packaging is a type of waste which, by its nature, represents a source of recoverable resources and is therefore present in directives and laws, focused primarily on the food industry. It has not been specifically treated to date in the construction field, hence the reason that justifies this work. This Thesis aims to improve the management of packaging waste from construction materials. An important set of residential building works with 1173 dwellings is analysed, which leads to knowledge on the production patterns of packaging waste (PW) in the construction industry, and the identification of the products responsible for its generation. The monitorization also allows for the design of specific strategies which minimise the generation of waste and optimize recovery. It has been found that the individualized treatment of PW can improve the results of the management of the whole CDW since, when not mixed, a major pollutant of inert waste is removed. The analysed works reached a very low segregation level and the façades and building services phases account for more than 50% of the overall PW. Focusing on each type of material, cardboard predominates electricity works, plastic on partitions and wood on façades. Eco-‐redesign is evaluated for one of the predominant packages, and strategies are identified to minimise their impact are . There is evidence that the savings in the CDW management in case of promoting segregation on site are not very significant at the studied works, although economic feasibility is the most important factor to motivate the construction companies. Public Administrations should encourage responsible management, establishing control measures in treatment plants and implementing CDW management exemplary measures on their work sites for the market. A proper planning of the works and specific training for the personnel are measures that facilitate in situ segregation and improve outcomes. The developers, through their contractual relationship with the other agents, have the ability to set reduction targets, planning and sustainable management of PW. Finally, a management system for PW is proposed, integrated within the Management System of the construction company, which aims to avoid that recoverable waste such as packaging is sent to landfill, leading the industry towards a more environmentally friendly future, aligned with sustainable development.
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Seamounts, submarine banks, volcanoes and undercurrent channels are prominent geomorphic features that have become an important target for minerals research and exploration with the goal of future exploitation. Polymetallic ferromanganese deposits are common types of mineralization on these settings. Co-rich ferromanganese crusts are important as potential resources of Mn and Co, but also Ti, Ni, Tl, REEs, PGEs, and other metals. Many seamounts and channels along the Atlantic Spanish continental margin are known to hold mineral deposits but are poorly studied. This work presents and briefly describes the most recent activities of the Spanish Geological Survey (IGME) on exploration and investigation of ferromanganese deposits along the Atlantic Spanish continental margin. Different submarine areas from the northwestern margin of the Iberian Peninsula to the west off Canary Islands have been surveyed by geophysical, sampling and underwater observations from 89 to 4000 m water depth. The mineral deposits cover a large diversity of submarine geological and geomorphical features: mud volcanoes and diapirs related to hydrocarbon seeps, seamounts associated with hot spot volcanism, hydrothermal vents in active magmatic volcanoes, structural basement highs and banks or contourite channels. Considering the collected dataset, we present the preliminary results of the study of these mineral deposits, including ferromanganese nodules and crusts and phosphate pavements and nodules, which can be considered as potential sources of raw materials.
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The effect of biochar on the soil carbon mineral- ization priming effect depends on the characteristics of the raw materials, production method and pyrolysis conditions. The goal of the present study is to evaluate the impact of three different types of biochar on physicochemical properties and CO2 emissions of a sandy loam soil. For this purpose, soil was amended with three different biochars (BI, BII and BIII) at a rate of 8 wt % and soil CO2 emissions were measured for 45 days. BI is produced from a mixed wood sieving from wood chip production, BII from a mixture of paper sludge and wheat husks and BIII from sewage sludge. Cumulative CO2 emissions of biochars, soil and amended soil were well fit to a simple first-order kinetic model with correlation coef- ficients (r 2 ) greater than 0.97. Results show a negative prim- ing effect in the soil after addition of BI and a positive prim- ing effect in the case of soil amended with BII and BIII. These results can be related to different biochar properties such as carbon content, carbon aromaticity, volatile matter, fixed carbon, easily oxidized organic carbon or metal and phenolic substance content in addition to surface biochar properties. Three biochars increased the values of soil field capacity and wilting point, while effects over pH and cation exchange capacity were not observed.
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La gasificación de lodos de depuración es una alternativa atractiva para generar gases combustibles como H2 y CO. A su vez, estos gases pueden emplearse como materias primas para la obtención de productos químicos orgánicos y combustibles líquidos. Sin embargo, la gasificación no está exenta de problemas como el ligado a la generación de residuos sólidos y alquitrán. El alquitrán en el gas puede ser un inconveniente para emplear el gas como combustible por las obstrucciones y corrosión en los equipos. Dado que las condiciones de gasificación influyen en la producción de alquitrán, este trabajo de investigación se ha centrado en analizar la influencia de parámetros como la temperatura, la carga de alimentación, el tamaño de partícula, el agente gasificante y la utilización de catalizadores en la gasificación en lecho fluidizado de lodos de depuración. Adicionalmente a la medición del efecto de los anteriores parámetros en la producción y composición del alquitrán, también se ha cuantificado su influencia en la producción y composición del gas y en producción del residuo carbonoso. Los resultados muestran que el incremento de la carga de alimentación (kg/h.m2) provoca el descenso de la producción de gas combustible y el incremento del residuo carbonoso y del alquitrán debido a la reducción del tiempo de residencia del gas lo que supone un menor tiempo disponible para las reacciones gas-gas y gas-sólido ligadas a la conversión del alquitrán y del residuo carbonoso en gases combustibles. También se ha comprobado que, el aumento del tamaño de partícula, al incrementar el tiempo de calentamiento de ésta, tiene un efecto similar en los productos de la gasificación que el derivado del incremento en la carga de alimentación. La utilización de una temperatura de gasificación alta (850 ºC), el empleo de aire-vapor como agente gasificante y/o catalizadores primarios como la dolomía consiguen reducir la producción de alquitrán. ABSTRACT Gasification of sewage sludge is an attractive alternative for generating of fuel gases such as H2 and CO. These gases, in turn, can be used as raw materials for the production of organic chemicals and liquid fuel. However, gasification is not without problems as the linked ones to production of char and tar. The tar in the gas can be an inconvenience for to use it as fuel by the problems of blockage and corrosion in the equipments. Since the gasification conditions affect the production of tar, this research has focused on analysing the influence of parameters such as temperature, throughput, the particle size, the gasifying agent and the use of catalysts in the fluidized bed gasification of sewage sludge. In addition to measuring the effect of the above parameters on the production and composition of the tar, it has also been quantified their influence on the yield and composition of the gas and char production. The results show that higher throughput (kg/h.m2) leads to a reduction of fuel gas production and an increase in the production of char and tar, this owes to a lower of gas residence time or what is the same thing less time available for gas-solid and gas-gas reactions attached to the conversion of tar and char to fuel gases. There has also been proven that the rising in particle size, by the increasing heating time of it, has a similar effect in the products of gasification that the results by the rise in the throughput. The applications a high gasification temperature (850 ° C), the use of air-steam as gasifying agent and/or dolomite as primary catalysts are able to reduce the production of tar.