Дисертації з теми "PILOT FUELS"

Biomass waste has been recognised as a promising, renewable source for future transport fuels. With 1.7 million hectares of pine plantation forests and 12 million cubic meters of annual residue produced by sawmills and the pulp and paper industries, New Zealand presents a prime location where utilisation of these resources can take the next step towards creating a more environmentally friendly future. In this research, the process of fast pyrolysis was investigated using a laboratoryscale, nitrogen-blown fluidised bed pyrolyser at CRL Energy. This equipment can process 1–1.5 kg/h of woody biomass in a temperature range of 450–550°C. The purpose of this rig was to determine the impact of various processing parameters on bio-oil yields. Next, the pyrolysis liquids (bio-oil and tar) were processed downstream into bio-bitumen. Pyrolysis experiments were carried out on Pinus Radiata and Eucalyptus Nitens residue sawdust from sawmills and bark feedstock. The properties of the collected products, including pyrolysis liquids (bio-oil and tar), gas and solid bio-chars, were measured under different operational conditions. Further analysis was also performed to determine pH, volatile content, chemical composition and calorific values of the products. The ultimate goal for this project was to develop a feasible, advanced fast-pyrolysis system for a bio-bitumen production plant using various biomass feedstocks. Additionally, a design for a bio-bitumen production plant was developed, and techno-economic analysis was conducted on a number of plant production yield cases and bio-bitumen manufacture ratios.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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This research studies making an intelligent tutoring system in order to reduce pilot mistakes during inflight emergency, specifically the flight environment within an F-4 aircraft fuel system malfunction. The pilot emergency tutoring system consists of an expert system with knowledge of the F=4 aircraft fuel system and a tutoring system with strategy to teach students. The expert and tutoring systems use a means-ends analysis problem approach, The means-ends analysis approach reduces differences between the current state and goal state until the final state or an unsolvable state is reached. Through use of the program, pilots can learn to prevent decision-making errors and procedural errors. Consequently, the pilot can be freer to serve as aircraft commander during an emergency situation.

This thesis focuses on enhancing knowledge on co-firing oxy-combustion cycles to boost development of this valuable technology towards the aim of it becoming an integral part of the energy mix. For this goal, the present work has addressed the engineering issues with regards to operating a retrofitted multi-fuel combustor pilot plant, as well as the development of a rate-based simulation model designed using Aspen Plus®. This model can estimate the gas composition and adiabatic flame temperatures achieved in the oxy-combustion process using coal, biomass, and coal-biomass blends. The fuels used for this study have been Daw Mill coal, El Cerrejon coal and cereal co-product. A parametric study has been performed using the pilot-scale 100kWth oxy-combustor at Cranfield University and varying the percentage of recycle flue gas, the type of recycle flue gas (wet or dry), and the excess oxygen supplied to the burner under oxy-firing conditions. Experimental trials using co-firing with air were carried out as well in order to establish the reference cases. From these tests, experimental data on gas composition (including SO3 measurement), temperatures along the rig, heat flux in the radiative zone, ash deposits characterisation (using ESEM/EDX and XRD techniques), carbon in fly ash, and acid dew point in the recycle path (using an electrochemical noise probe), were obtained. It was clearly shown during the three experimental campaigns carried out, that a critical parameter was that of minimising the air ingress into the process as it was shown to change markedly the chemistry inside the oxy-combustor. Finally, part of the experimental data collected (related to gas composition and temperatures) has been used to validate the kinetic simulation model developed in Aspen Plus®. For this validation, a parametric study considering the factor that most affect the oxy-combustion process (the above mentioned excess amount of air ingress) was varied. The model was found to be in a very good agreement with the empirical results regarding the gas composition.

Wastewater is increasingly considered a resource rather than a problem. This study investigates the rapidly developing Microbial Fuel Cell technology and its potential to be used in an industrial scale and environment in the context of the whisky industry and to be used as an alternative or complementary sustainable wastewater treatment process. This study describes the development of a 122 litre multi-electrode open air cathode Microbial Fuel Cell. Throughout this study the reactor’s performance is assessed on two levels; energy recovery and effluent quality. During initial studies the principle of the MFC’s ability to treat whisky distillation by-products was established. The reactor was operated directly on diluted spent wash in ambient Scottish temperatures. During successful start-up, no correlation was found to temperature. During long-term operation, a positive correlation was found between temperature and the positive energy balance achieved by the MFC while tCOD removal efficiency was maintained at approximately 83 %. The reactor was further optimised in regards to electrical connections, thus its electrical performance which was also validated through a bench scale study. The successful initial experiments led to the integration of an operationally optimised pilot study in a local whisky distillery. The pilot set-up was successfully operated complementary to an anaerobic digester for over one year in the industrial environment achieving energy savings and a sustainable tCOD removal efficiency of over 80 %. Latterly, a simplified electrochemical model was examined to describe the performance of the MFC to be further developed. This study concludes that the nature of industrial wastewater treatment is a complex subject and equally so is the multi-disciplinary MFC technology. The MFC developed for this study and the industrial experience gained contributes towards a more sustainable, energy saving and efficient treatment technology with the potential to be used complementary to existing technologies.

More deaths are caused every year by indoor air pollution than malaria, HIV/AIDS and tuberculosis combined. Cooking with traditional fuels such as charcoal and fuelwood with poor ventilation causes the single most important environmental health risk factor worldwide. It also contributes to environmental issues such as deforestation as traditional biomass fuels and cooking stoves are inefficient and requires large quantities of wood. This is especially critical in Africa where the largest regional population growth in the world is expected to occur. A solution to these issues was realized through fuel pellets and modern cooking stoves by Emerging Cooking Solutions, a company started by two Swedes and based in Zambia. The production of fuel pellets in Zambia is dependent on pine sawdust from small sawmills and is a declining source of raw material. However, other sources of biomass are available in Zambia such as pigeon pea stalk, an agricultural waste product, and sicklebush, an invasive tree species. If these species are viable for pelletization, the production of pellets can increase while reducing issues with sicklebush and promoting cultivation of pigeon pea. The aim of this work is to evaluate if pigeon pea stalk and sicklebush are viable to pelletize in Zambia and how the press is affected by the different raw materials. A pilot study is done at Karlstad University with a single unit press, hardness tester and soxhlet extractor to evaluate how the material constituents correlate to friction in the press channel and hardness of the pellets. The results of the pilot study provide support for full scale tests done in a pellet plant in Zambia. The normal production of pellets from pine sawdust is used as quality and production reference for the tests with pigeon pea stalk, sicklebush, and different mixes of the raw materials. The properties used to evaluate the quality of the pellets are hardness, durability, moisture content, bulk density, and fines. The press configuration is evaluated by logging the electricity consumption by the press motor, calculating the power and specific energy consumption from the logs, and observations during the tests. The results show that sicklebush, and mixes of sicklebush with pigeon pea stalk can produce pellets with better quality than the reference pine pellets. An interesting composition is a mix of 80% pigeon pea and 20% sicklebush that produces pellets with the best quality of all the tests. However, pellets produced from sicklebush and pigeon pea show a larger variation in hardness as compared to the reference pellets from pine sawdust. Mixing pigeon pea with pine reduces these variations but reduces the hardness of the pellets below the reference. The press struggles to process sicklebush and pigeon pea stalk with fluctuating power consumption that causes the motor to trip. The inhomogeneity of the materials in sicklebush and pigeon pea are identified to cause the issues in the press. Production improvements are discussed to facilitate the production of pigeon pea stalk and sicklebush pellets.

La ricerca nel campo dei motori a combustione interna è sempre più rivolta ad identificare una soluzione alternativa all’utilizzo dei combustibili derivati dal petrolio, per ragioni di carattere ambientale, politico ed economico. Il gas naturale (NG) è un combustibile ideale per motori a combustione interna, essendo caratterizzato da basso impatto ambientale e consumi ridotti rispetto ai combustibili convenzionali (benzina e gasolio). Inoltre esso è particolarmente adatto ad essere utilizzato in motori ad elevato rapporto di compressione volumetrico, ed è caratterizzato da un ampio campo di infiammabilità. Quest’ultimo aspetto promuove la combustione magra di miscele di aria e NG, ottenendo un ulteriore incremento di rendimento ed un’ulteriore diminuzione dei consumi. I motori dual-fuel NG/diesel permettono di estendere il limite magro d’infiammabilità rispetto ai motori ad accensione comandata alimentati a NG, ed allo stesso tempo consentono di ridurre il trade-off NOX-PM di cui soffrono i motori diesel. Tale tecnologia consiste nell’introduzione del NG come combustibile principale in un motore diesel. Una certa quantità di gasolio viene ancora iniettata, ed agisce come sorgente d’accensione per la miscela di aria e NG. La facilità di conversione rende la tecnologia dual-fuel particolarmente allettante come retrofit di motori diesel già esistenti che in futuro si troverebbero a non soddisfare i sempre più stringenti limiti sulle emissioni inquinanti. Nel presente lavoro, la combustione dual-fuel, con la sua inerente complessità, viene analizzata seguendo un approccio misto numerico-sperimentale. L’attività sperimentale ha come obiettivo l’analisi dei vantaggi e dei problemi connessi con la conversione di un motore diesel heavy-duty al funzionamento dual-fuel, sulla base delle prestazioni e delle emissioni inquinanti. L’attività numerica è caratterizza da un approccio misto 1-D/3-D, ed è stata inizialmente condotta per la corretta comprensione del complesso meccanismo di combustione in modalità dual-fuel. L’analisi multi-dimensionale (3-D) dettagliata del sistema cilindro–pistone è stata successivamente effettuata per la corretta rappresentazione dei fenomeni termo-fluidodinamici evolventi in camera di combustione. Una tale strategia permette la completa descrizione del comportamento dell’intero sistema motore e della combustione dual-fuel nel dettaglio.
The research activity on internal combustion engines is increasingly cast to find an alternative solution to reduce the wide utilization of petroleum fuels like diesel oil and gasoline, for environmental, political and economic concerns. Natural gas (NG) is an ideal fuel to be operated in internal combustion engines, since its characteristics allow for much lower environmental impact and reduced fuel consumption with respect the conventional fuels. It also is particularly suitable to be operated under high volumetric compression ratio engines, thus providing higher efficiency, and moreover it is characterized by a wide flammability range. This latter aspect promotes the employment of a lean burn strategy, thus further increasing the engine efficiency and reducing the exhaust emissions. The dual-fuel natural gas/diesel concept allows extending the lean flammability limit of NG with respect to SI-NG operations and simultaneously reducing the NOX-PM trade-off affecting diesel combustion. Such a technology consists in introducing NG as main fuel in a conventional diesel engine. A certain amount of diesel pilot injection is preserved to act as the ignition source for the air/NG mixture. The easiness of dual-fuel conversion makes such technology rather inviting especially as a retrofit for the existing diesel vehicles, which could not meet the more and more stringent emission regulations in the future. In the present study, the dual-fuel combustion process with its inherent complexity is investigated both from an experimental and a numerical point of view. The experimental activity has the main target to analyze the problems connected with the conversion of a heavy-duty diesel engine to dual-fuel operation, and to put into evidence the influence of the main engine parameters on performance and pollutants formation. The numerical activity, characterized by a mixed 1-D/3-D approach, has been carried out with the initial target of a correct understanding of the complex dual-fuel combustion mechanism. A detailed multi-dimensional simulation of the whole working cycle of the engine has been subsequently performed, to provide for the correct representation of the fluid-dynamic effect involved in dual-fuel operations. Such an approach allows for the complete description of the engine overall behavior and the dual-fuel combustion in detail.

La dégradation de l’environnement ainsi que l’épuisement progressif des énergies fossiles devient très inquiétant et incite les états à définir des limites d’émission polluantes plus strictes. Ceci a conduit les constructeurs automobiles à poursuivre leurs recherches dans le développement de conception propre et efficace des moteurs en utilisant des combustibles alternatifs dans les moteurs à combustion interne.Dans le présent travail, on s’intéresse à l’étude des moteurs fonctionnant en mode DF afin d’améliorer ses performances tout en minimisant les émissions polluantes, en particulier les HC et les CO. Pour ce faire des études expérimentales ont été menées. Une réduction de 77% des émissions de HC a été observée en passant d’une richesse de 0,35 à 0,7. Par ailleurs, Il a été noté aussi qu’une diminution de 20% à 50% des émissions de CO avec une amélioration de 30% du rendement peut être visualisée en variant l’avance à l’injection de 4,5 °V à 6 °V. Concernant la mise en place de la pré-injection, une baisse de 30% des émissions de NOx a été observée avec un gain de 12% à 30% de rendement par rapport à une seule injection. En dernier terme, un modèle thermodynamique à une zone a été développé afin de prédire la température et la pression dans le cylindre. Une bonne concordance a été notée entre les deux résultats avec une erreur moyenne relative inférieure à 5%
Currently, the environmental degradation due to pollutant emissions and the gradual depletion of fossil fuels, becoming very worrying, are prompting European directives to set pollutant emission limits. These have led manufacturers to continue research in the development of clean and efficient engine designs using alternative fuels in internal combustion engines.In this work, we focus on the study of engines operating in dual-fuel mode to improve its performance while minimizing pollutant emissions, particularly HC and CO. For this, experimental studies were conducted. A reduction of about 77% in the HC emissions was observed as the equivalence ratio was varied from 0.35 to 0.7. Regarding the effect of injection timing, it was noted that the CO emissions decreased about 20% to 50% with an improvement in the brake thermal efficiency by 30% upon varying the injection advance from 4,5 °CA to 6 °CA. On the other hand, the introduction of pre-injection strategy led to a decrease by 30% in NOx emissions with an amelioration of brake thermal efficiency of 12% to 30% compared to a single injection. Lastly, a single zone thermodynamic model was developed to predict the in-cylinder temperature and pressure. A good agreement was noted between the predicted and experimental results. The average relative error was less than 5%

Le biogaz doit être purifié pour devenir un combustible renouvelable. De nombreux traitements actuels ne sont pas satisfaisants car, pour des raisons de coûts les procédés de séparation privilégiés aboutissent souvent au rejet direct ou indirect du sulfure d'hydrogène (H2S) à l’atmosphère, c’est le cas de la séparation à l’eau sous pression. Les objectifs de la thèse portent d’abord sur l’étude et la modélisation des méthodes connues de séparation de l'hydrogène sulfuré du méthane. Les concentrations typiques varient de 200 à 5000 ppm, et la séparation devra réduire la teneur résiduelle en H2S à moins de 1 ppm. Parallèlement seront étudiées les méthodes de traitement de H2S. Une fois la (ou les) méthode(s) de séparation sélectionnée(s), des essais de validation seront effectués sur un système traitant de l’ordre de 85 Nm3/h de méthane où seront injectées des quantités de H2S variant entre 1 et 100 ppm.Cette thèse requiert des modélisations réalistes sous Aspen Plus® ou sous un code équivalent pour établir a priori des efficacités de séparation selon différentes conditions opératoires et en prenant en compte le paramètre température. L’énergie dépensée pour la séparation effective sera un des critères fort de la comparaison, de même que l’économie de matière.Une approche système est indispensable pour étudier la rétroaction de la méthode de valorisation du H2S sur la ou les méthodes séparatives. A priori c’est aussi l’outil Aspen Plus® ou équivalent qui permettra cette approche système.L’étude du procédé sera menée selon la double approche modélisation et expérimentation, pour l’étude expérimentale des méthodes séparatives, l’échelle du banc sera semi-industrielle et le banc permettra d’étudier les méthodes de séparation jusqu’à -90°C
Biogas must be purified for becoming a renewable fuel. At now, the most part of the purification techniques are not satisfactory because they imply hydrogen sulfides (H2S) rejection to the atmosphere. One example of these methods is the treatment with high pressure water. The first objective of the thesis is modeling the conventional methods for separating H2S from methane. Typical concentrations of H2S in methane vary from 200 to 5000 pm. Separation methods must decrease the concentration of H2S in methane to less than 1 ppm. At the same time, methods for H2S treatment will be studied.Once the most appropriated separation methods will be selected, some test will be carried out on a pilot plant capable of treating 85 Nm3/h of methane, where quantities of H2S ranging from 1 and 100 ppm will be injected. These tests will allow validating the modeling of the separation process. On the basis of the obtained results, a specific test bench will be conceived and constructed for validating the selected process.The thesis work requires simulating the separation process using the software Aspen Plus® or an equivalent one. The effectiveness of different operative conditions will be tested, varying also the parameter temperature. The energy necessary for the separation will be one of the most important criteria for the comparison, as well as the mass consumption of the different fluids involved in the process.A system approach is fundamental for evaluating the backward effect of the H2S valorization method on the separation techniques. The process simulator (Aspen Plus® or equivalent) will allow the system approach.The study will involve modeling and experimental parts. The experimental part will be carried out taking advantage of a semi-industrial size test bench, allowing studying the separation methods down to -90°C

Les travaux de cette thèse ont pour but de développer un prototype d’éco-pilote, nommé EcoNav, permettant d’optimiser la vitesse d’un bateau afin de réduire sa consommation de carburant. EcoNav est composé de plusieurs modules dont : un modèle hydraulique 2D simulant l’écoulement hydrodynamique (vitesse du courant et hauteur d’eau) le long du trajet du bateau; - un modèle de résistance à l’avancement servant à alimenter un modèle de prédiction de la consommation de carburant; - un algorithme d’optimisation permettant de trouver le profil optimal de vitesse. Afin de pouvoir estimer la consommation de carburant, un modèle numérique de la résistance à l’avancement en milieu confiné a été développé durant la première partie de cette thèse. Ce modèle numérique 3D simule l’écoulement du fluide autour du bateau et permet de calculer les forces agissant sur sa coque. La résolution des équations RANS est couplée avec un algorithme de quasi-Newton afin de trouver la position d’équilibre du bateau et calculer son enfoncement. Cette méthode est validée en comparant les résultats numériques avec des résultats expérimentaux issus d’essais en bassin de traction. L’influence de l’enfoncement sur la résistance à l’avancement et la précision de la méthode est étudiée en comparant les résultats numériques obtenus avec et sans enfoncement. La précision des modèles empiriques de prédiction de la résistance à l’avancement est également comparée à celle du modèle numérique. Enfin, le modèle numérique est utilisé afin de déterminer si le confinement en largeur ou en profondeur ont une influence identique sur l’augmentation de résistance à l’avancement. Les résultats de cette étude permettent d’établir si le confinement de la voie d’eau peut être caractérisé à l’aide d’un paramètre unique (coefficient de blocage par exemple) ou bien deux paramètres permettant de distinguer le confinement latéral et vertical. Dans la seconde partie de cette thèse, les méthodes numériques utilisées pour le modèle d’éco-pilote sont décrites et comparées afin de sélectionner celles qui sont le plus adaptées à chaque module. EcoNav est ensuite utilisé afin de modéliser un cas réel : celui du bateau automoteur Oural navigant sur la Seine entre Chatou et Poses (153 km). La consommation optimisée est comparée à la consommation non optimisée, calculée à partir des vitesses AIS observées sur le tronçon étudié. L’influence de la trajectoire du bateau et de son temps de parcours sur sa consommation sont également étudiés. Les résultats de ces investigations ont montré qu’optimiser la vitesse du bateau permet d’obtenir une réduction de la consommation de carburant de l’ordre de 8 % et qu’optimiser la trajectoire du bateau ainsi que prendre en compte des informations en temps réel (disponibilité des écluses, trafic sur le fleuve) peuvent permettre de réaliser des économies de carburant supplémentaires
An eco-driving prototype, named EcoNav, is developed with the aim of optimizing a vessel speed in order to reduce fuel consumption for a given itinerary. EcoNav is organized in several modules : - a 2D hydraulic model simulating the flow conditions (current speed and water depth) along the itinerary; - a ship resistance model calculating the thrust necessary to counteract the hydrodynamic forces ; - a fuel consumption model calculating the fuel consumption corresponding to the thrust input; - a non linear optimization algorithm calculating the optimal speed profile. In order to evaluate the fuel consumption of an inland vessel, a ship resistance numerical model is developed in the first part of this PhD. This 3D numerical model simulates the flow around an inland self-propelled vessel and evaluates the hydrodynamic forces acting on the hull. A RANS solver is coupled with a quasi-Newton approach to find the equilibrium position and calculate ship sinkage. This method is validated by comparing the results of numerical simulations to towing tank tests. The numerical results with and without sinkage are also compared to study the influence of sinkage on ship resistance and on the accuracy of the method. Additionally, some empirical models are investigated and compared with the accuracy of the numerical method. Finally, the numerical model is used to determine if channel with and water depth restriction contribute to the same amount of ship resistance increase for the same level of restriction. The results of that investigation give insight to whether channel restriction can be characterized by a unique parameter (for instance the blockage ratio) or two parameters to distinguish water depth and channel with effects. In the second part of this PhD, the numerical methods used in the speed optimization model are described and validated. The speed optimization model is then used to simulate a real case: the itinerary of the self-propelled ship Oural on river Seine, between Chatou and Poses (153 km). The optimized fuel consumption is compared with the non-optimized fuel consumption, based on AIS speed profile retrieved on this itinerary. The effects of the ship trajectory and travel duration on fuel consumption are also investigated. The results of those investigations showed that optimizing the ship speed lead to an average fuel saving of 8 % and that using an optimal track and including real time information such as lock availability and river traffic can lead to additional fuel savings

Industrial dependence on energy and international conflicts has triggered the fuel prices to new highs. As a result, new alternative fuels must be explored that have no or very less harmful emissions without the compromise of the efficiency. One such fuel that can be converted for use in internal combustion engines is biogas. In this experimental study, a Direct Injection Compression Ignition (DICI) engine is converted into a dual-fuel engine that runs on biogas as primary fuel and various fuel blends as the pilot fuel. It will achieve the goal of lower exhaust emissions although the thermal efficiency remains nearby same. Diesel, biodiesel, alcohol and their blends are used as the pilot fuel, whereas biogas-air mixture is injected through intake manifold. Engine air intake system is upgraded to allow the combination of air and biogas to mix thoroughly before being fed to the cylinder. The engine performance and emission characteristics are measured and compared with conventional diesel engine. The findings of this investigation revealed that a DICI engine can efficiently be converted into a dual-fuel engine that runs on both diesel and biogas. Brake thermal efficiency decreases from 33.23% (in diesel mode) to 18.86% in dual fuel mode due to the lower calorific value of biogas compared to diesel. Whereas, the exhaust emissions like HC, CO, and CO2 are also measured and found a increment in their percentage but for NOx percentage was reduced r. Further, the results shows that the ratio 80:20 (i.e., 20% SBDO and 80% biogas) can be used in diesel engine with a very little reduction in engine performance; thus, saving about 80% of the conventional diesel fuel. Therefore, the engine performance characteristics reveal that a considerable amount of diesel can be saved with addition of biogas in dual-fuel mode.

An experimental study of the effects of turbulent flow regime on the flame structure is conducted by using perforated-plate-stabilized hydrogen-piloted lean premixed methane/air turbulent flames. The underlying non-reacting turbulent flow field was investigated using two-dimensional three-components particle imaging velocimetry (2D3C-PIV) with and without three perforated plates. The non-reacting flow data allowed a separation of the turbulent flow regime into axial velocity dominated and vortex dominated flows. A plate with 62\% blockage ratio was used to represent the stream-dominant flow regime and another with 86\% blockage ratio was used to represent the vortex-dominant flow regime. OH laser-induced fluorescence was used to study the effects of the turbulent flow regime on the mean progress variable, flame brush thickness, flame surface density, and global consumption speed. In comparison with the stream-dominant flow, the vortex-dominant flow makes a wider and shorter flame. Also, the vortex-dominant flow has a thicker horizontal flame brush thickness and a thinner longitudinal flame brush thickness. Especially, the horizontal flame brush thickness for the vortex-dominant flow does not follow the turbulence diffusion theory. Then, the vortex-dominant flow shows a relatively constant flame surface density along the stream-wise direction, while the stream-dominant flow shows a decreasing flame surface density. Lastly, the vortex-dominant turbulent flow improves the consumption speed in comparison to the stream-dominant turbulent flow regime with the same velocity fluctuation level.

碩士
中原大學
化學工程研究所
104
In recent years, energy recovery is one of methods for waste disposal, and the focus is mostly laid on the solid waste. However, the reports on the treatment of liquid wastes are very few, and the behavior of liquid wastes during combustion is differed from that of solid waste. This study is to investigate the behavior and pollutant emissions during co-combustion of coal and liquid fuel. Experiments in this study are carried out in the pilot-scale vortexing fluidized bed which is 0.8 m length × 0.4 m width × 4.7 m height. In the case of fixed total heat release(130,000 kcal/hr), using liquid waste, jatropha oil and coal as fuel. Total primary air is 3 Nm3/min and excess air is 50%. The bed temperature and liquid-fuel ratio are adjusted to explore the effect of operating conditions on the temperature of furnace, combustion fraction and NOx emissions. The results show that the in-bed combustion fraction in the case of co-combustion of solid and liquid increases with the bed temperature, but decreases with the ratio of the liquid increases. The NOx emissions increases with bed temperature. As the liquid fuel increases, depending on the amount of nitrogen content, the results varied; if the nitrogen content of the liquid fuels is higher than that of the coal, nitrogen oxide emissions will increase accordingly, and vice versa.

Fuel cells are electrochemical energy devices that convert the chemical energy in a fuel into electrical energy. Although they are more efficient, clean, and reliable than fossil fuel combustion systems, they have not been widely adopted because of manufacturing challenges and high production cost. The most expensive component of a fuel cell is the membrane electrode assembly (MEA), which consists of an ionomer membrane coated with catalyst material. Best performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane, however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. This work models the swelling and drying phenomena of the membrane and coating during manufacturing, and then applies the results to develop and control a continuous coating line for the production of defect free fuel cell MEAs. A continuous coating line can reduce the costs and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. Membrane swelling is a three-dimensional, transient, coupled mass transfer, heat transfer, and solid mechanics problem. Existing models describe the membrane’s behavior in operating conditions, but none predict the behavior during manufacturing. This work develops a novel physics-based model that describes the behavior of the membrane and coating in a continuous manufacturing scenario and incorporates effects that are missing from existing models. A model that can predict wrinkles, the most commonly observed defect during manufacturing, is presented. Simulation results from the above models are used to design and develop an improved continuous MEA coating process that includes pre-swelling and two-stage drying of the coated membrane. A prototype pilot-scale coating line to implement and test the improved coating process is designed and constructed. Finally, a Linear-Quadratic-Gaussian type controller is developed using the physics-based model of the manufacturing process to optimally control the temperature and humidity of the drying zones, and its effectiveness when implemented on the coating line is discussed.
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“Fresh Fuel: The CanU Food Club” (Fresh Fuel) is the food and nutrition component of the larger CanU program aimed at improving the future well being of vulnerable children. A mixed-method case study evaluation was conducted with Fresh Fuel, employing a Utilization-Focused Evaluation approach. Results suggested that there were some gains in Fresh Fuel Participant (FFP) food and nutrition outcomes. Also, there were a variety of social benefits to FFPs, such as positive interaction with volunteers and peers, and having fun. Volunteers and practicum students developed career goals and skills. Results identified incompatible program goals, time limitations, inconsistent program implementation, and lack of direction in nutrition education; however, Fresh Fuel provided a supportive environment, hands on learning, and included positive nutrition discussions and food preparation experiences. The Utilization-Focused Evaluation approach has resulted in a meaningful report. Rigorous evaluations of Fresh Fuel and other food and nutrition programs are recommended.
October 2015

Ethanol is playing a key role in current discussions on energy, agriculture, taxes and the environment. This work addresses the potential environmental impacts and behavior of subsurface fuel-ethanol releases. A continuous-flow 8,150-L pilot-aquifer tank packed with sand was used to simulate two spill scenarios: (1) fuel-grade ethanol (E95, 95% v/v ethanol, 5% v/v hydrocarbon mixture as a denaturant) into uncontaminated soil, and (2) neat ethanol (100% v/v) release onto gasoline-contaminated soil. Measurement of ethanol and hydrocarbon concentrations in groundwater and capillary-fringe pore water from over 30-locations over 120+ days provided a quantitative evaluation of the extent of plume migration, longevity, and impacts to groundwater quality. Real-time quantitative PCR (RTQ-PCR) was also used to estimate temporal and spatial trends in concentrations of total bacteria (16s rDNA) and various genotypes that inhabit different electron-accepting zones at sites undergoing natural attenuation. Furthermore, the anaerobic catabolic gene bssA (coding for benzylsuccinate synthase), and the aerobic catabolic genes dmpN (coding for phenol hydroxylase) and todC1 (coding for toluene dioxygenase) were also quantified as biomarkers for BTEX biodegradation. Ethanol, which is buoyant and hygroscopic, quickly migrated upwards and spread laterally within the capillary-zone. Horizontal migration of ethanol occurred through a shallow thin layer with minimal vertical dispersion, and was consistently 10-times slower than the preceding bromide tracer. Dyes, one hydrophobic (Sudan-IV) and one hydrophilic (Fluorescein) provided evidence that the fuel hydrocarbons phase separated from the E95 mixture as ethanol was diluted by pore water and its cosolvent effect was diminished. The neat ethanol spill mobilized the pre-existing hydrocarbon NAPL down-gradient. Neither of the highly concentrated spills had a bactericidal impact on the microbial community, and cell growth coincided with ethanol availability. Bacteria concentrations increased by at least one-order of magnitude as did bacteria harboring todC1 and dmpN after each spill. However, bacteria harboring bssA were not detected, suggesting that longer acclimation time may be required to establish anaerobic hydrocarbon degraders. It appears that microbial impacts are mainly related to O 2 depletion, but rebound can be relatively fast, and fortuitous proliferation of aerobic BTEX degraders (growing on ethanol) is likely following the relatively rapid ethanol washout.

Approximately 2.5 billion people in the world currently lack access to adequate sanitation facilities. Improving sanitation access in the developing world is vitally important to public health, economies, and the environment. Non-governmental organizations and the private sector have played a significant role in increasing sanitation access through the construction of sanitation and hygiene systems. However, these projects have been plagued with sustainability problems with the rate of non-functional systems remaining consistently at 30 to 40 percent since the 1980s. Studies have found that meaningful community engagement and the consideration of community capacity during project development are vitally important to long-term project sustainability. However, development practitioners frequently undervalue the importance of these factors and fail to adequately employ them when developing sanitation projects. This thesis examines the dominance and impact of one key influence that leads development practitioners to overlook community context and engagement – the prioritization and overvaluation of technological solutions to development problems. Through a case study of the Microbial Fuel Cell (MFC) Latrine built by three University of Massachusetts Amherst engineers in Nyakrom Ghana I demonstrate an example of the impact that a technocratic focus can have on the operation and maintenance sustainability of a sanitation project. In this thesis I maintain that the technocratic focus of this project is not unique but is part of a larger trend toward technocracy among water, sanitation, and hygiene development donors and practitioners. These technological approaches can neglect the important role that political, social, economic, and cultural factors play in increasing sanitation access. This thesis reviews three frameworks that the MFC Latrine engineers and other practitioners could use to better understand and incorporate community capacity and participation into sanitation projects – Asset Based Community Development, the appropriate technology framework by the World Health Organization and IRC Water and Sanitation Centre, and the WASHTech Technology Applicability Framework.

Combustion with a high surface area continuous solid immersed within the flame, referred to as combustion in porous media, is an innovative approach to combustion as the solid within the flame acts as an internal regenerator distributing heat from the combustion byproducts to the upstream reactants. By including the solid structure, radiative energy extraction becomes viable, while the solid enables a vast extension of flammability limits compared to conventional flames, while offering dramatically reduced emissions of NOx and CO, and dramatically increased burning velocities. Efforts documented within are used for the development of a streamlined set of design principles, and characterization of the flame's behavior when operating under such conditions, to aid in the development of future combustors for lean burn applications in open flow systems. Principles described herein were developed from a combination of experimental work and reactor network modeling using CHEMKIN-PRO. Experimental work consisted of a parametric analysis of operating conditions pertaining to reactant flow, combustion chamber geometric considerations and the viability of liquid fuel applications. Experimental behavior observed, when utilizing gaseous fuels, was then used to validate model outputs through comparing thermal outputs of both systems. Specific details pertaining to a streamlined chemical mechanism to be used in simulations, included within the appendix, and characterization of surface area of the porous solid are also discussed. Beyond modeling the experimental system, considerations are also undertaken to examine the applicability of exhaust gas recirculation and staged combustion as a means of controlling the thermal and environmental output of porous combustion systems. This work was supported by ACS PRF "51768-ND10 and NSF IIP 1343454.
M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Thermo-Fluids Track