Geochemistry and mineralogy of coal samples from Dingji Mine, Huainan Coalfield, China

To investigate the geochemistry of trace elements in coals from the Dingji Mine of the Huainan Coalfield, Anhui province, China, 416 borehole samples of coal, one parting, two floor and two roof mudstones were collected from 9 minable coal seams in 24 boreholes drilled during exploration. The abundances of 47 elements in each sample were determined by various instruments. The boron concentration in the coals suggests that marine influence decreased from coal seam 1 to 13-1. The geometric means of the elements Sn, Bi, Sb, and B are higher than the average for the corresponding elements in the coals from China, the U.S., and world. The enrichment of certain elements in the Shanxi or Upper Shihezi Formations is related to their depositional environment. The roof, floor and parting samples have higher contents of some elements than coal seams. The mineral matters in the coals from the Dingji Mine were found to consist mainly of granular quartz, clay minerals, and carbonate minerals. The elements are classified into two groups based on their stratigraphic distribution from coal seam 1 to 13-1, and the characteristics of each group are discussed. Based on the correlation coefficients of elemental concentrations with ash yield, four groups of elements with different affinities were identified.

Assessment of self-combustion risks for solid fuels (POSTER)

Every solid fuel has a tendency to react with oxygen, a fact that constitutes the basis of their ability to oxidation and energy intake for combustion, but that poses a risk when it occurs in an uncontrolled manner. When the slow oxidation phenomenon produces more heat than can be evacuated, the result is a heating process, which promotes combustion reactions, primarily fuel oxidation, and a progressive increase in temperature.

Coal purchase optimization: a review from Spain

The study addresses the need to manage the risk of the purchase price of coal in a power company by changing the management model of the purchasing department. It eliminates the risk of price reduces the cost of buying coal and optimizing the performance of all electricity generation plants belonging to the company. You get more flexibility and optionallity to gain additional benefits both economic and efficiency in the supply to our generation fleet. The tools to achieve the above purpose will be financial derivatives that will be used as elements of management and not as mere speculation in the markets.

PAH occurrence during combustion of biodiesel from various feedstocks

PAHs are pollutants of concern since they are known carcinogenic compounds. Their occurrence is mainly related to combustion or pyrolysis of organic matter such as fossil fuels. In the current scenario where biofuels are growingly important, it is also necessary to characterize PAH emissions due to their combustion. There are a number of works concerning PAH emissions from biodiesel combustion in Diesel engines, however, there are few regarding the difference between them depending on the feedstock and type of alcohol used in the transesterification. The authors have processed and characterized biodiesel from several feedstocks (Le. tallow, palm, rapeseed, soy-bean, coconut, peanut and linseed oils) to obtain FAME and FAEE and they have developed a method to measure the PAHs originated during their combustion in a bomb calorimeter. The tests have been carried out under different oxygen pressure conditions, and samples have been c1eaned from the bomb after each one of these tests. The samples have been prepared for GC-MS analysis, where PAH quantities among some other combustion products have been assessed. This work shows statistical relations obtained between the measured amounts of 18 PAHs of concern and the composition (oil and type of alcohol) used to obtain the biodiesel, and also the oxygen pressure during combustion.

On the formation of nitrogen oxides in the combustion processes of hydrogen in air

A research programme is being carried out at the Institute Nacional de Tecnica Aeroespacial of Spain, on several aspects of the formation of nitrogen oxides in continuous flow combustion systems, considering hydrogen and hydrocarbons as fuels. The research programme is fundamentally oriented on the basic aspects of the problem, although it also includes the study of the influence on the formation process of several operational and design variables of the combusters, such as type of fuels, fuel/air ratio, degree of mixing in premixed type flames, existence of droplets as compared with homogeneous combustion.This problem of nitrogen oxides formation is receiving lately great attention, specially in connection with automobile reciprocating engines and aircraft gas turbines. This is due to the fact of the increasing frequency and intensity of photochemical hazes or smog, typical of urban areas submitted to strong solar radiation, which are originated by the action on organic compounds of the oxidants resulting from the photochemical decomposition of nitrogen dioxide N02. In the combustion process almost all nitrogen oxides are in form of NO. This nitric oxide reacts with the oxygen of the air and forms N02, this reaction only taking place in or near the exhaust of tne motors, since the N0-02 reaction becomes frozen for the concentration existing in the atmosphere.

Explosion risk in coke, coal and sulphur storage

The self-ignition of all kind of powdery substances is a topic studied over the years, especially if the dusty substance is coal or substances related with coal because it may be a cause of energetic materials and human losses. But it is important to note that this is not the only risk in industrial plants that generate or store solid substances. Every combustible powders are potentially explosive and they may cause serious consequences if all the necessary factors are developed. Due to this potentially risk, it is essential a good characterization and knowledge of all the parameters involved in those processes.

Flammability properties of dry sewage sludges

Dry sewage sludge are being considered as a possible energy source for direct firing. They have interesting properties to be used as an alternative fuel, but also other characteristics must be considered from the point of view of its safe operation: the most important are ignition sensitivity, explosion severity, thermal sensitivity and thermal stability. The aim of this study was to determine if sewage sludge have different characteristics due to different locations or seasons and how this influences their flammability properties. To study these characteristics sludge samples were selected from different locations in Spain, taken during different seasons. In addition, relationships between flammability parameters and chemical analysis were observed. Some parameters can be controlled during normal operation, such as granulometry or humidity, and may mean a decrease in the risk of explosion. Those relationships are well known for other dusts materials, like coal, but not yet for sewage sludge dusts. Finally, properties related to spontaneous combustion were determined (thermal susceptibility and stability). The addition of those properties to the study provides an overview of the thermal behavior of sewage sludge during their utilization, including transport and storage.

Flammability conditions for ultra-lean hydrogen premixed combustion based on flame-ball analyses

It has been reasoned that the structures of strongly cellular flames in very lean mixtures approach an array of flame balls, each burning as if it were isolated, thereby indicating a connection between the critical conditions required for existence of steady flame balls and those necessary for occurrence of self-sustained premixed combustion. This is the starting assumption of the present study, in which structures of near-limit steady sphericosym-metrical flame balls are investigated with the objective of providing analytic expressions for critical combustion conditions in ultra-lean hydrogen-oxygen mixtures diluted with N2 and water vapor. If attention were restricted to planar premixed flames, then the lean-limit mole fraction of H2 would be found to be roughly ten percent, more than twice the observed flammability limits, thereby emphasizing the relevance of the flame-ball phenomena. Numerical integrations using detailed models for chemistry and radiation show that a onestep chemical-kinetic reduced mechanism based on steady-state assumptions for all chemical intermediates, together with a simple, optically thin approximation for water-vapor radiation, can be used to compute near-limit fuel-lean flame balls with excellent accuracy. The previously developed one-step reaction rate includes a crossover temperature that determines in the first approximation a chemical-kinetic lean limit below which combustión cannot occur, with critical conditions achieved when the diffusion-controlled radiation-free peak temperature, computed with account taken of hydrogen Soret diffusion, is equal to the crossover temperature. First-order corrections are found by activation-energy asymptotics in a solution that involves a near-field radiation-free zone surrounding a spherical flame sheet, together with a far-field radiation-conduction balance for the temperature profile. Different scalings are found depending on whether or not the surrounding atmosphere contains wáter vapor, leading to different analytic expressions for the critical conditions for flame-ball existence, which give results in very good agreement with those obtained by detailed numerical computations.

Simulation of an Integrated Gasification Combined Cycle with Chemical-Looping Combustion and CO2 sequestration

Chemical-looping combustion allows an integration of CO2 capture in a thermal power plant without energy penalty; secondly, a less exergy destruction in the combustion chemical transformation is achieved, leading to a greater overall thermal efficiency. This paper focus on the study of the energetic performance of this concept of combustion in an integrated gasification combined cycle power plant when synthesis gas is used as fuel for the gas turbines. After thermodynamic modelling and optimization of some cycle parameters, the power plant performance is evaluated under diverse working conditions and compared to a conventional integrated gasification combined cycle with precombustion capture. Energy savings in CO2 capture and storage has been quantified. The overall efficiency increase is found to be significant and even notable, reaching values of around 7%. In order to analyze the influence of syngas composition on the results, different H2-content fuels are considered.

A model for turbulent combustion simulation of large scale hydrogen explosions

El agotamiento, la ausencia o, simplemente, la incertidumbre sobre la cantidad de las reservas de combustibles fósiles se añaden a la variabilidad de los precios y a la creciente inestabilidad en la cadena de aprovisionamiento para crear fuertes incentivos para el desarrollo de fuentes y vectores energéticos alternativos. El atractivo de hidrógeno como vector energético es muy alto en un contexto que abarca, además, fuertes inquietudes por parte de la población sobre la contaminación y las emisiones de gases de efecto invernadero. Debido a su excelente impacto ambiental, la aceptación pública del nuevo vector energético dependería, a priori, del control de los riesgos asociados su manipulación y almacenamiento. Entre estos, la existencia de un innegable riesgo de explosión aparece como el principal inconveniente de este combustible alternativo. Esta tesis investiga la modelización numérica de explosiones en grandes volúmenes, centrándose en la simulación de la combustión turbulenta en grandes dominios de cálculo en los que la resolución que es alcanzable está fuertemente limitada. En la introducción, se aborda una descripción general de los procesos de explosión. Se concluye que las restricciones en la resolución de los cálculos hacen necesario el modelado de los procesos de turbulencia y de combustión. Posteriormente, se realiza una revisión crítica de las metodologías disponibles tanto para turbulencia como para combustión, que se lleva a cabo señalando las fortalezas, deficiencias e idoneidad de cada una de las metodologías. Como conclusión de esta investigación, se obtiene que la única estrategia viable para el modelado de la combustión, teniendo en cuenta las limitaciones existentes, es la utilización de una expresión que describa la velocidad de combustión turbulenta en función de distintos parámetros. Este tipo de modelos se denominan Modelos de velocidad de llama turbulenta y permiten cerrar una ecuación de balance para la variable de progreso de combustión. Como conclusión también se ha obtenido, que la solución más adecuada para la simulación de la turbulencia es la utilización de diferentes metodologías para la simulación de la turbulencia, LES o RANS, en función de la geometría y de las restricciones en la resolución de cada problema particular. Sobre la base de estos hallazgos, el crea de un modelo de combustión en el marco de los modelos de velocidad de la llama turbulenta. La metodología propuesta es capaz de superar las deficiencias existentes en los modelos disponibles para aquellos problemas en los que se precisa realizar cálculos con una resolución moderada o baja. Particularmente, el modelo utiliza un algoritmo heurístico para impedir el crecimiento del espesor de la llama, una deficiencia que lastraba el célebre modelo de Zimont. Bajo este enfoque, el énfasis del análisis se centra en la determinación de la velocidad de combustión, tanto laminar como turbulenta. La velocidad de combustión laminar se determina a través de una nueva formulación capaz de tener en cuenta la influencia simultánea en la velocidad de combustión laminar de la relación de equivalencia, la temperatura, la presión y la dilución con vapor de agua. La formulación obtenida es válida para un dominio de temperaturas, presiones y dilución con vapor de agua más extenso de cualquiera de las formulaciones previamente disponibles. Por otra parte, el cálculo de la velocidad de combustión turbulenta puede ser abordado mediante el uso de correlaciones que permiten el la determinación de esta magnitud en función de distintos parámetros. Con el objetivo de seleccionar la formulación más adecuada, se ha realizado una comparación entre los resultados obtenidos con diversas expresiones y los resultados obtenidos en los experimentos. Se concluye que la ecuación debida a Schmidt es la más adecuada teniendo en cuenta las condiciones del estudio. A continuación, se analiza la importancia de las inestabilidades de la llama en la propagación de los frentes de combustión. Su relevancia resulta significativa para mezclas pobres en combustible en las que la intensidad de la turbulencia permanece moderada. Estas condiciones son importantes dado que son habituales en los accidentes que ocurren en las centrales nucleares. Por ello, se lleva a cabo la creación de un modelo que permita estimar el efecto de las inestabilidades, y en concreto de la inestabilidad acústica-paramétrica, en la velocidad de propagación de llama. El modelado incluye la derivación matemática de la formulación heurística de Bauwebs et al. para el cálculo de la incremento de la velocidad de combustión debido a las inestabilidades de la llama, así como el análisis de la estabilidad de las llamas con respecto a una perturbación cíclica. Por último, los resultados se combinan para concluir el modelado de la inestabilidad acústica-paramétrica. Tras finalizar esta fase, la investigación se centro en la aplicación del modelo desarrollado en varios problemas de importancia para la seguridad industrial y el posterior análisis de los resultados y la comparación de los mismos con los datos experimentales correspondientes. Concretamente, se abordo la simulación de explosiones en túneles y en contenedores, con y sin gradiente de concentración y ventilación. Como resultados generales, se logra validar el modelo confirmando su idoneidad para estos problemas. Como última tarea, se ha realizado un analisis en profundidad de la catástrofe de Fukushima-Daiichi. El objetivo del análisis es determinar la cantidad de hidrógeno que explotó en el reactor número uno, en contraste con los otros estudios sobre el tema que se han centrado en la determinación de la cantidad de hidrógeno generado durante el accidente. Como resultado de la investigación, se determinó que la cantidad más probable de hidrogeno que fue consumida durante la explosión fue de 130 kg. Es un hecho notable el que la combustión de una relativamente pequeña cantidad de hidrogeno pueda causar un daño tan significativo. Esta es una muestra de la importancia de este tipo de investigaciones. Las ramas de la industria para las que el modelo desarrollado será de interés abarca la totalidad de la futura economía de hidrógeno (pilas de combustible, vehículos, almacenamiento energético, etc) con un impacto especial en los sectores del transporte y la energía nuclear, tanto para las tecnologías de fisión y fusión. ABSTRACT The exhaustion, absolute absence or simply the uncertainty on the amount of the reserves of fossil fuels sources added to the variability of their prices and the increasing instability and difficulties on the supply chain are strong incentives for the development of alternative energy sources and carriers. The attractiveness of hydrogen in a context that additionally comprehends concerns on pollution and emissions is very high. Due to its excellent environmental impact, the public acceptance of the new energetic vector will depend on the risk associated to its handling and storage. Fromthese, the danger of a severe explosion appears as the major drawback of this alternative fuel. This thesis investigates the numerical modeling of large scale explosions, focusing on the simulation of turbulent combustion in large domains where the resolution achievable is forcefully limited. In the introduction, a general description of explosion process is undertaken. It is concluded that the restrictions of resolution makes necessary the modeling of the turbulence and combustion processes. Subsequently, a critical review of the available methodologies for both turbulence and combustion is carried out pointing out their strengths and deficiencies. As a conclusion of this investigation, it appears clear that the only viable methodology for combustion modeling is the utilization of an expression for the turbulent burning velocity to close a balance equation for the combustion progress variable, a model of the Turbulent flame velocity kind. Also, that depending on the particular resolution restriction of each problem and on its geometry the utilization of different simulation methodologies, LES or RANS, is the most adequate solution for modeling the turbulence. Based on these findings, the candidate undertakes the creation of a combustion model in the framework of turbulent flame speed methodology which is able to overcome the deficiencies of the available ones for low resolution problems. Particularly, the model utilizes a heuristic algorithm to maintain the thickness of the flame brush under control, a serious deficiency of the Zimont model. Under the approach utilized by the candidate, the emphasis of the analysis lays on the accurate determination of the burning velocity, both laminar and turbulent. On one side, the laminar burning velocity is determined through a newly developed correlation which is able to describe the simultaneous influence of the equivalence ratio, temperature, steam dilution and pressure on the laminar burning velocity. The formulation obtained is valid for a larger domain of temperature, steam dilution and pressure than any of the previously available formulations. On the other side, a certain number of turbulent burning velocity correlations are available in the literature. For the selection of the most suitable, they have been compared with experiments and ranked, with the outcome that the formulation due to Schmidt was the most adequate for the conditions studied. Subsequently, the role of the flame instabilities on the development of explosions is assessed. Their significance appears to be of importance for lean mixtures in which the turbulence intensity remains moderate. These are important conditions which are typical for accidents on Nuclear Power Plants. Therefore, the creation of a model to account for the instabilities, and concretely, the acoustic parametric instability is undertaken. This encloses the mathematical derivation of the heuristic formulation of Bauwebs et al. for the calculation of the burning velocity enhancement due to flame instabilities as well as the analysis of the stability of flames with respect to a cyclic velocity perturbation. The results are combined to build a model of the acoustic-parametric instability. The following task in this research has been to apply the model developed to several problems significant for the industrial safety and the subsequent analysis of the results and comparison with the corresponding experimental data was performed. As a part of such task simulations of explosions in a tunnel and explosions in large containers, with and without gradient of concentration and venting have been carried out. As a general outcome, the validation of the model is achieved, confirming its suitability for the problems addressed. As a last and final undertaking, a thorough study of the Fukushima-Daiichi catastrophe has been carried out. The analysis performed aims at the determination of the amount of hydrogen participating on the explosion that happened in the reactor one, in contrast with other analysis centered on the amount of hydrogen generated during the accident. As an outcome of the research, it was determined that the most probable amount of hydrogen exploding during the catastrophe was 130 kg. It is remarkable that the combustion of such a small quantity of material can cause tremendous damage. This is an indication of the importance of these types of investigations. The industrial branches that can benefit from the applications of the model developed in this thesis include the whole future hydrogen economy, as well as nuclear safety both in fusion and fission technology.

Influencia de las restricciones medioambientales en el sector eléctrico

El objetivo de esta tesis es la caracterización de la generación térmica representativa de la existente en la realidad, para posteriormente proceder a su modelización y simulación integrándolas en una red eléctrica tipo y llevar a cabo estudios de optimización multiobjetivo económico medioambiental. Para ello, en primera instancia se analiza el contexto energético y eléctrico actual, y más concretamente el peninsular, en el que habiendo desaparecido las centrales de fuelóleo, sólo quedan ciclos combinados y centrales de carbón de distinto rango. Seguidamente se lleva a cabo un análisis de los principales impactos medioambientales de las centrales eléctricas basadas en combustión, representados sobre todo por sus emisiones de CO2, SO2 y NOx, de las medidas de control y mitigación de las mismas y de la normativa que les aplica. A continuación, a partir de las características de los combustibles y de la información de los consumos específicos, se caracterizan los grupos térmicos frente a las funciones relevantes que definen su comportamiento energético, económico y medioambiental, en términos de funciones de salida horarias dependiendo de la carga. Se tiene en cuenta la posibilidad de desnitrificación y desulfuración. Dado que las funciones objetivo son múltiples, y que están en conflicto unas con otras, se ha optado por usar métodos multiobjetivo que son capaces de identificar el contorno de puntos óptimos o frente de Pareto, en los que tomando una solución no existe otra que lo mejore en alguna de las funciones objetivo sin empeorarlo en otra. Se analizaron varios métodos de optimización multiobjetivo y se seleccionó el de las ε constraint, capaz de encontrar frentes no convexos y cuya optimalidad estricta se puede comprobar. Se integró una representación equilibrada de centrales de antracita, hulla nacional e importada, lignito y ciclos combinados en la red tipo IEEE-57, en la que se puede trabajar con siete centrales sin distorsionar demasiado las potencias nominales reales de los grupos, y se programó en Matlab la resolución de flujos óptimos de carga en alterna con el método multiobjetivo integrado. Se identifican los frentes de Pareto de las combinaciones de coste y cada uno de los tres tipos de emisión, y también el de los cuatro objetivos juntos, obteniendo los resultados de costes óptimos del sistema para todo el rango de emisiones. Se valora cuánto le cuesta al sistema reducir una tonelada adicional de cualquier tipo de emisión a base de desplazarse a combinaciones de generación más limpias. Los puntos encontrados aseguran que bajo unas determinadas emisiones no pueden ser mejorados económicamente, o que atendiendo a ese coste no se puede reducir más allá el sistema en lo relativo a emisiones. También se indica cómo usar los frentes de Pareto para trazar estrategias óptimas de producción ante cambios horarios de carga. ABSTRACT The aim of this thesis is the characterization of electrical generation based on combustion processes representative of the actual power plants, for the latter modelling and simulation of an electrical grid and the development of economic- environmental multiobjective optimization studies. In this line, the first step taken is the analysis of the current energetic and electrical framework, focused on the peninsular one, where the fuel power plants have been shut down, and the only ones remaining are coal units of different types and combined cycle. Then it is carried out an analysis of the main environmental impacts of the thermal power plants, represented basically by the emissions of CO2, SO2 y NOx, their control and reduction measures and the applicable regulations. Next, based on the combustibles properties and the information about the units heat rates, the different power plants are characterized in relation to the outstanding functions that define their energy, economic and environmental behaviour, in terms of hourly output functions depending on their load. Optional denitrification and desulfurization is considered. Given that there are multiple objectives, and that they go in conflictive directions, it has been decided the use of multiobjective techniques, that have the ability of identifying the optimal points set, which is called the Pareto front, where taken a solution there will be no other point that can beat the former in an objective without worsening it in another objective. Several multiobjective optimization methods were analysed and pondered, selecting the ε constraint technique, which is able to find no convex fronts and it is opened to be tested to prove the strict Pareto optimality of the obtained solutions. A balanced representation of the thermal power plants, formed by anthracite, lignite, bituminous national and imported coals and combined cycle, was integrated in the IEEE-57 network case. This system was selected because it deals with a total power that will admit seven units without distorting significantly the actual size of the power plants. Next, an AC optimal power flow with the multiobjective method implemented in the routines was programmed. The Pareto fronts of the combination of operative costs with each of the three emissions functions were found, and also the front of all of them together. The optimal production costs of the system for all the emissions range were obtained. It is also evaluated the cost of reducing an additional emission ton of any of the emissions when the optimal production mix is displaced towards cleaner points. The obtained solutions assure that under a determined level of emissions they cannot be improved economically or, in the other way, at a determined cost it cannot be found points of lesser emissions. The Pareto fronts are also applied for the search of optimal strategic paths to follow the hourly load changes.

Aprovechamiento térmico de residuos estériles de carbón para generación eléctrica mediante tecnologías de combustión y gasificación eficientes y con mínimo impacto ambiental

La presente tesis doctoral, “Aprovechamiento térmico de residuos estériles de carbón para generación eléctrica mediante tecnologías de combustión y gasificación eficientes y con mínimo impacto ambiental”, desarrolla la valorización energética de los residuos del carbón, estériles de carbón, producidos durante las etapas de extracción y lavado del carbón. El sistema energético se encuentra en una encrucijada, estamos asistiendo a un cambio en el paradigma energético y, en concreto, en el sector de la generación eléctrica. Se precipita un cambio en la generación y el consumo eléctricos. Una mayor concienciación por la salud está forzando la contención y eliminación de agentes contaminantes que se generan por la utilización de combustibles fósiles de la forma en la que se viene haciendo. Aumenta la preocupación por el cambio climático y por contener en 2°C el aumento de la temperatura de la Tierra para final de este siglo, circunstancia que está impulsando el desarrollo e implantación definitiva de tecnología de control y reducción de emisiones CO2. Generar electricidad de una manera sostenible se está convirtiendo en una obligación. Esto se materializa en generar electricidad respetando el medioambiente, de una forma eficiente en la utilización de los recursos naturales y a un coste competitivo, pensando en el desarrollo de la sociedad y en el beneficio de las personas. En la actualidad, el carbón es la principal fuente de energía utilizada para generar electricidad, y su empleo presenta la forma de energía más barata para mejorar el nivel de vida de cualquier grupo y sociedad. Además, se espera que el carbón siga presente en el mix de generación eléctrica, manteniendo una significativa presencia y extrayéndose en elevadas cantidades. Pero la producción de carbón lleva asociada la generación de un residuo, estéril, que se produce durante la extracción y el lavado del mineral de carbón. Durante décadas se ha estudiado la posibilidad de utilizar el estéril y actualmente se utiliza, en un limitado porcentaje, en la construcción de carreteras, terraplenes y rellenos, y en la producción de algunos materiales de construcción. Esta tesis doctoral aborda la valorización energética del estéril, y analiza el potencial aprovechamiento del residuo para generar electricidad, en una instalación que integre tecnología disponible para minimizar el impacto medioambiental. Además, persigue aprovechar el significativo contenido en azufre que presenta el estéril para producir ácido sulfúrico (H2SO4) como subproducto de la instalación, un compuesto químico muy demandado por la industria de los fertilizantes y con multitud de aplicaciones en otros mercados. Se ha realizado el análisis de caracterización del estéril, los parámetros significativos y los valores de referencia para su empleo como combustible, encontrándose que su empleo como combustible para generar electricidad es posible. Aunque en España se lleva extrayendo carbón desde principios del siglo XVIII, se ha evaluado para un período más reciente la disponibilidad del recurso en España y la normativa existente que condiciona su aplicación en el territorio nacional. Para el período evaluado, se ha calculado que podrían estar disponibles más de 68 millones de toneladas de estéril susceptibles de ser valorizados energéticamente. Una vez realizado el análisis de la tecnología disponible y que podría considerarse para emplear el estéril como combustible, se proponen cuatro configuraciones posibles de planta, tres de ellas basadas en un proceso de combustión y una de ellas en un proceso de gasificación. Tras evaluar las cuatro configuraciones por su interés tecnológico, innovador y económico, se desarrolla el análisis conceptual de una de ellas, basada en un proceso de combustión. La instalación propuesta tiene una capacidad de 65 MW y emplea como combustible una mezcla de carbón y estéril en relación 20/80 en peso. La instalación integra tecnología para eliminar en un 99,8% el SO2 presente en el gas de combustión y en más de un 99% las partículas generadas. La instalación incorpora una unidad de producción de H2SO4, capaz de producir 18,5 t/h de producto, y otra unidad de captura para retirar un 60% del CO2 presente en la corriente de gases de combustión, produciendo 48 tCO2/h. La potencia neta de la planta es 49,7 MW. Se ha calculado el coste de inversión de la instalación, y su cálculo resulta en un coste de inversión unitario de 3.685 €/kW. ABSTRACT The present doctoral thesis, “Thermal utilisation of waste coal for electricity generation by deployment of efficient combustion and gasification technologies with minimum environmental impact”, develops an innovative waste-to-energy concept of waste coals produced during coal mining and washing. The energy system is at a dilemma, we are witnessing a shift in the energy paradigm and specifically in the field of electricity generation. A change in the generation and electrical consumption is foreseen. An increased health consciousness is forcing the containment and elimination of pollutants that are generated by the use of fossil fuels in the way that is being done. Increasing concern about climate change and to contain the rise of global temperature by 2°C by the end of this century, is promoting the development and final implementation of technology to control and reduce the CO2 emission. Electricity generation in a sustainable manner is becoming an obligation. This concept materialised in generating electricity while protecting the environment and deployment of natural resources at a competitive cost, considering the development of society and people´s benefit. Currently, coal is the main source of energy employ to generate electricity, and its use represents the most cost competitive form of energy to increase the standard of living of any group or society. Moreover, coal will keep playing a key role in the global electricity generation mix, maintaining a significant presence and being extracting in large amounts. However, coal production implies the production of waste, termed waste coal or culm in Pennsylvania anthracite extraction, produced during coal mining and coal washing activities. During the last decades, the potential use of waste coal has been studied, and currently, in a limited amount, waste coal is used in roads construction, embankments and fillings, and to produce some construction materials. This doctoral thesis evaluates the waste to energy of waste coals and assesses its potential use to generate electricity, implementing available technology to minimise the environment impact. Additionally, it pursues the significant advantage that presents sulphur content in waste coal to produce sulphuric acid (H2SO4) as a byproduct of the waste-to-energy process, a chemical compound highly demanded by the fertiliser industry and many applications in other markets. It analyses the characteristics of waste coal, and assesses the significant parameters and reference values for its use as fuel, being its fuel use for electricity generation very possible. While mining coal is taking place in Spain since the 1700s, it has been evaluated for a more recent period the waste coal available in Spain and the existing legislation that affects its application and deploy to generate electricity in the country. For the evaluation period has been calculated that may be available more than 68 million tons of waste coal that can be waste-toenergy. The potential available technology to deploy waste coal as fuel has been evaluated and assessed. After considering this, the doctoral thesis proposes four innovative alternatives of facility configuration, three of them based on a combustion process and one in a gasification process. After evaluating the four configurations for its technological, innovative and economic interest, the conceptual analysis of one of alternatives, based on a combustion process, takes place. The proposed alternative facility developed has a capacity of 65 MW, using as fuel a mixture of coal and waste coal 80/20 by weight. The facility comprises technology to remove 99.8% SO2 present in the flue gas and more than 99% of the particles. The facility includes a unit capable of producing 18.5 t/h of H2SO4, and another capture facility, removing 60% of CO2 present in the flue gas stream, producing 48 tCO2/h. The net capacity of the power station is 49.7 MW. The facility unitary cost of investment is 3,685 €/kW.

Integrated Water Resources Management: Principles for Coordination in the Coal River Watershed, West Virginia

Mountaintop removal (MTR) coal mining has had a significant influence on the water sources within the Coal River watershed of West Virginia. Using an approach such as Integrated Water Resources Management (IWRM) may improve management for the long-term protection and sustainability of the Coal River watershed‰Ûªs water resources. This Capstone project analyzes current site-specific information related to water quality and quantity and the impacts of MTR in the region, reviews current management challenges, and identifies key stakeholders to be included in IWRM planning. This information provided a foundation for the development of a preliminary IWRM coordination plan for the Coal River watershed based on IWRM principles and guidelines. It is hoped that this preliminary plan will contribute to the development of a final coordinated IWRM plan.