abstract: With a recent shift to a more environmentally conscious society, low-carbon and non-carbon producing energy production methods are being investigated and applied all over the world. Of these methods, fuel cells show great potential for clean energy production. A fuel cell is an electrochemical energy conversion device which directly converts chemical energy into electrical energy. Proton exchange membrane fuel cells (PEMFCs) are a highly researched energy source for automotive and stationary power applications. In order to produce the power required to meet Department of Energy requirements, platinum (Pt) must be used as a catalyst material in PEMFCs. Platinum, however, is very expensive and extensive research is being conducted to develop ways to reduce the amount of platinum used in PEMFCs. In the current study, three catalyst synthesis techniques were investigated and evaluated on their effectiveness to produce platinum-on copper (Pt@Cu) core-shell nanocatalyst on multi-walled carbon nanotube (MWCNT) support material. These three methods were direct deposition method, two-phase surfactant method, and single-phase surfactant method, in which direct deposition did not use a surfactant for particle size control and the surfactant methods did. The catalyst materials synthesized were evaluated by visual inspection and fuel cell performance. Samples which produced high fuel cell power output were evaluated using transmission electron microscopy (TEM) imaging. After evaluation, it was concluded that the direct deposition technique was effective in synthesizing Pt@Cu core-shell nanocatalyst on MWCNTs support when a rinsing process was used before adding platinum. The peak power density achieved by the rinsed core-shell catalyst was 618 mW.cm-2 , 13 percent greater than that of commercial platinum-carbon (Pt/C) catalyst. Transmission electron microscopy imaging revealed the core-shell catalyst contained Pt shells and platinum-copper alloy cores. Rinsing with deionized (DI) water was shown to be a crucial step in core-shell catalyst deposition as it reduced the number of platinum colloids on the carbon nanotube surface. After evaluation, it was concluded that the two-phase surfactant and single-phase surfactant synthesis methods were not effective at producing core-shell nanocatalyst with the parameters investigated. / Dissertation/Thesis / M.S.Tech Technology 2012

abstract: Photovoltaic (PV) modules are typically rated at three test conditions: STC (standard test conditions), NOCT (nominal operating cell temperature) and Low E (low irradiance). The current thesis deals with the power rating of PV modules at twenty-three test conditions as per the recent International Electrotechnical Commission (IEC) standard of IEC 61853 – 1. In the current research, an automation software tool developed by a previous researcher of ASU – PRL (ASU Photovoltaic Reliability Laboratory) is validated at various stages. Also in the current research, the power rating of PV modules for four different manufacturers is carried out according to IEC 61853 – 1 standard using a new outdoor test method. The new outdoor method described in this thesis is very different from the one reported by a previous researcher of ASU – PRL. The new method was designed to reduce the labor hours in collecting the current-voltage ( I – V) curves at various temperatures and irradiance levels. The power matrices for all the four manufacturers were generated using the I – V data generated at different temperatures and irradiance levels and the translation procedures described in IEC 60891 standard. All the measurements were carried out on both clear and cloudy days using an automated 2 – axis tracker located at ASU – PRL, Mesa, Arizona. The modules were left on the 2 – axis tracker for 12 continuous days and the data was continuously and automatically collected for every two minutes from 6 am to 6 pm. In order to obtain the I – V data at wide range of temperatures and irradiance levels, four identical (or nearly identical) modules were simultaneously installed on the 2 – axis tracker with and without thermal insulators on the back of the modules and with and without mesh screens on the front of the modules. Several issues related to the automation software were uncovered and the required improvement in the software has been suggested. The power matrices for four manufacturers have been successfully generated using the new outdoor test method developed in this work. The data generated in this work has been extensively analyzed for accuracy and for performance efficiency comparison at various temperatures and irradiance levels. / Dissertation/Thesis / M.S.Tech Technology 2012

ALVES, Gustavo Henrique de Oliveira Estudo do aproveitamento das espécies vegetais Sabiá (Mimosa caesalpiniaefolia Benth.) e Capim-elefante (Pennisetum purpureum Schum.) para fins energéticos no Estado de Alagoas. 2013. 76 f. Dissertação (Mestrado em Engenharia Química) – Centro de Tecnologia, Programa de Pós Graduação em Engenharia Química, Universidade Federal de Alagoas, Maceió, 2013. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A busca por fontes de energias alternativas tem-se constituído como um dos principais desafios da sociedade atual. Neste contexto a biomassa vem ganhando espaço, pois é considerada uma fonte energética renovável e de baixo custo. Dentre as espécies vegetais disponíveis no Estado de Alagoas, o Sabiá (Mimosa caesalpiniaefolia Benth.) e o Capim-elefante (Pennisetum purpureum Schum.) mostram-se bastante promissoras. Para tanto, se efetuaram estudos físico-químicos e energéticos dessas espécies, antes e após compactação. As folhas e o caule do Sabiá e os colmos e folhas do Capim-elefante foram triturados e em seguida realizou-se processos de secagem (quando necessário) e análise granulométrica. As folhas e caule demonstraram densidade variando de 0,72 a 0,82 g/cm3. Para as amostras não compactada e compactada a variação dos teores de voláteis foram de 60,62 a 79,09 %, para os teores de cinzas foram de 1,66 a 2,99 %, para os teores de carbono fixo de 19,25 a 36,39 % e os dados de poder calorífico superior (PCS) mostraram valores variando de 17.490,00 a 18.087,50 kJ/kg e de 15.847,64 a 16.455,14 kJ/kg para o poder calorífico inferior (PCI). As folhas e colmos do Capim-elefante (Cameroon e Roxo) apresentaram dados de densidade variando entre 0,51 e 0,71 g/cm3, teor de voláteis entre 66,45 e 77,32 %, teor de cinzas indo de 3,66 a 13,76 % e teor de carbono fixo de 10,08 a 23,39 %. Os PCS’s e PCI’s para as folhas do Capim-elefante forneceram valores mínimos de 16.408,00 kJ/kg e 14.785,40 kJ/kg, respectivamente. Para os colmos verde e roxo o PCS mínimo observado foi de 15.077,50 kJ/kg e o menor valor de PCI correspondeu a 13.428,79 kJ/kg. Desenvolveu-se um estudo simulando o cultivo energético das espécies em um assentamento rural do Estado de Alagoas, localizado próximo a uma cerâmica vermelha. Os resultados demonstraram que a floresta energética de Capim-elefante se mostra mais promissora do ponto de vista econômico/energético em relação à plantação de Sabiá.

A constituição de sistemas híbridos como alternativa ao fornecimento de energia da concessionária, gerando energia própria e operando de forma isolada ou interconectada ao sistema de distribuição, tem originado estudos e implementações em nível industrial, comercial e mais recentemente residencial. A principal discussão que surge são as análises das vantagens técnicas e econômicas pela opção desse tipo de instalação. Neste trabalho, é apresentado um estudo complementar às pesquisas realizadas, onde é projetado um sistema híbrido contendo aerogeradores, painéis fotovoltaicos, processo de eletrólise, célula a combustível, microturbina a gás e geradores diesel. Esse sistema é simulado e comparado técnica e economicamente a um sistema que contém apenas geradores diesel. O sistema híbrido proposto possui uma microrrede conectada a um típico sistema de distribuição mas com um limite de demanda contratada que impede a satisfação de todas as necessidades energéticas da instalação apenas com a energia da concessionária. Procura-se avaliar os impactos técnicos e econômicos do atendimento da demanda por eletricidade através deste sistema híbrido além de executar-se a otimização, via PSO, do dimensionamento deste sistema, que utiliza uma ordem de despacho para gerenciar as mini unidades geradoras de energia. Foi utilizado o software TRNSYS devido a sua característica de permitir estimar a potência e energia produzidas no intervalo de um ano com detalhamento horário de cada recurso, considerando estimativas reais e localizadas para a disponibilidade dos recursos eólicos e fotovoltaicos. / The designing of hybrid systems as an alternative to power supply from power utility, generating their own energy in operating islanded or grid-tie to the power utility, has resulted in studies and implementations in industrial, commercial and residential level recently. The main discussion that arises is the analysis of the technical and economical advantages for this type of solution. This work presents a complementary study to the researches conducted nowadays, which is designed a hybrid system containing wind turbines, photovoltaic panels, electrolysis process, fuel cell, gas micro turbine and diesel generators. This system was simulated and was compared technically and economically to a system with only diesel gensets. The proposed hybrid system has a microrrede connected to a typical distribution system with a limited power demand value that prevents the satisfaction of all energy needs of the installation only with the utility power. This study evaluates the technical and economical impacts to meeting electric power consumption through this hybrid system and optimize using PSO, the design of this system that uses a dispatch order to manage the mini power generation units. The TRNSYS software was used due to its feature of allowing estimate the electric power and electric energy produced in one year apart with hourly details of each feature, considering actual estimates and localized availability of wind and photovoltaic resources.

The main concern of this dissertation is the establishment of experimental bases for the project, automation, and installation of a micro-power plant for electric power generation based on PEM fuel cell stacks (BCS Technology). The plant operates automatically, and its control is accomplished by a microcontroller acting directly in the temperature, in the humidity of the membrane, in the amount of reaction air, in the monitoring of the individual voltage of each cell and in the attempt of recovery of a possibly problematic cell. For control operation special auxiliary mechanisms are necessary to avoid dangerous conditions to the stack. The making of the prototype is of low cost and easily found items in national market access have been intended. Special controlled atmospheres were also designed and built to shelter the stack and obtain safety operation when the stack is on. Therefore, the work tries to find the theoretical and experimental bases for a static power plant implementation based on fuel cell systems. / O tema principal desta dissertação é o estabelecimento de bases experimentais para o projeto, automação e a instalação de uma microcentral de geração de energia elétrica com pilhas de células de combustível do tipo PEM (BCS Technology). Esta central deve operar automaticamente, comandada por microcontrolador que atua diretamente na temperatura, na umidade da membrana, na quantidade de ar de reação, no monitoramento da tensão individual de cada célula e na tentativa da recuperação de células problemáticas. Para que este controle atue são necessários mecanismos auxiliares especiais de forma a não causarem danos às células. Na confecção do protótipo procurou-se especificar dispositivos de baixo custo e de fácil disponibilidade no mercado nacional. Locais especiais também foram projetados e construídos para abrigar a pilha quando em operação de forma a garantir o máximo de segurança. Portanto, este trabalho busca fornecer bases teóricas e experimentais para a implementação de uma central estacionária de geração com pilhas de células de combustível.

Made available in DSpace on 2014-06-11T19:25:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-30Bitstream added on 2014-06-13T18:26:29Z : No. of bitstreams: 1 polettofilho_ja_me_bauru.pdf: 2436001 bytes, checksum: dea364a29d1b1548ee72860e0af7c826 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A exploração abusiva da energia originada de fontes não renováveis traz danos irreversíveis ao ambiente. O Brasil é dependente dos derivados do petróleo e das hidroelétrica. Diante desse contexto é necessário um estudo sobre outras fontes alternativas. Conciliar a geração de energia com possibilidade também de mitigar o impacto da geração de lixo seria resolver dois problemas de uma só vez. O objetivo do presente trabalho é analisar a recuperação de energia do Resíduo Sólido Urbano (RSU) através do processo de incineração. Leva em consideração a tendência atual de segregação (separação) de plásticos, papel e papelão, vidro e metais, e sua influência nos fluxos de massa e energia no sistema de incineração de RSU. Para o seu desenvolvimento foram utilizadas informações relativas à geração do RSU da cidade de Bauru e o software Combust. Os resultados obtidos permitiram estimar o poder calorífero teórico do RSU típico e também deste resíduo quando se considera a separação de papel/papelão e plásticos para fins de reciclagem. / The abusive exploration of the originated energy of no-renewable sources brings irreversible damages to the environment. In Brazil, it is dependent mainly of the derived or petroleum and of the hydroelectric ones. With base in that fact, the subject of the sources of energy is subject on the agenda globally. On the other hand, the wastes generation and the consequent environmental contamination, comes increased in an alarming way. Conciliate the generation of energy with possibility of mitigating the impact of the wastes generation it would be to solve two problems of only one time. The objective of the present work is to analyze the recovery of energy of the Municipal Solid Wastes (MSW) through of the incineration process. It considers the actual tendency of segregation of plastics, paper and cardboard, glass and metals, and your influences in the mass and energy flows in the incineration system of MSW. For the development of thiw work were used relative information to the MSW generation of Bauru city and the Combust software. The obtained results allowed esteeming the Theoretical Calorific Power of MSW typical and also of this residue when it is considered the paper / cardboard and plastics separation for recycling.

Doctor of Philosophy / Grain Science and Industry / Praveen V. Vadlani / Lignocellulosic biomass feedstocks are a sustainable resource required for rapid growth of bio-based industries. An integrated approach, including plant breeding, harvesting, handling, and conversion to fuels, chemicals and power, is required for the commercial viability of the lignocellulosic-based biorefineries. Optimization of conversion processes, including biomass pretreatment and hydrolysis, is a challenging task because of the distinct variations in composition and structure of biopolymers among biomass types. Efficient fermentation of biomass hydrolyzates comprising of different types of sugars is challenging. The purpose of this doctoral research was to evaluate and optimize the various processing steps in the entire the biomass value chain for efficient production of advanced biofuels and chemicals from diverse biomass feedstocks. Our results showed that densification of bulky biomass by pelleting to better streamline the handling and logistic issues improved pretreatment and hydrolysis efficiencies. Alkali pretreatment was significantly more effective than acid pretreatment at same processing conditions for grass and hardwood. The ethanol-isopropanol mixture, and glycerol with 0.4% (w/v) sodium hydroxide were the promising organic solvent systems for the pretreatment of corn stover (grass), and poplar (hardwood), respectively. None of the pretreatment methods used in this study worked well for Douglas fir (softwood), which indicates a need to further optimize appropriate processing conditions, better solvent and catalyst for effective pretreatment of this biomass. The brown midrib (bmr) mutations improved the biomass quality as a feedstock for biochemicals production in some sorghum cultivars and bmr types, while adverse effects were observed in others. These results indicated that each potential sorghum cultivar should be separately evaluated for each type of bmr mutation to develop the best sorghum line as an energy crop. Development of an appropriate biomass processing technology to generate separate cellulose and hemicellulose hydrolyzates is required for efficient 2,3-butanediol (BD) fermentation using a non-pathogenic bacterial strain, Bacillus licheniformis DSM 8785. This culture is significantly more efficient for BD fermentation in single sugar media than Klebsiella oxytoca ATCC 8724. Though K. oxytoca is a better culture reported so far for BD fermentation from diverse sugars media, but it is a biosafety level 2 organism, which limits its commercial potential.

Doctor of Philosophy / Agronomy / Charles W. Rice / Substitution of cellulosic biofuel in place of gasoline or diesel could reduce greenhouse gas (GHG) emissions from transportation. However, emissions of nitrous oxide (N₂O) and changes in soil organic carbon (SOC) could have a large impact on the GHG balance of cellulosic biofuel, thus there is a need to quantify these responses in cellulosic biofuel crops. The objectives of this study were to: (i) measure changes in yield, SOC and microbial communities in potential cellulosic biofuel cropping systems (ii) measure and characterize the temporal variation in N₂O emissions from these systems (iii) characterize the yield and N₂O response of switchgrass to N fertilizer and to estimate the costs of production. Sweet sorghum, photoperiod-sensitive sorghum, and miscanthus yielded the highest aboveground biomass (20-32 Mg ha⁻¹). The perennial grasses sequestered SOC over 4 yrs, while SOC stocks did not change in the annual crops. Root stocks were 4-8 times higher in the perennial crops, suggesting greater belowground C inputs. Arbuscular mycorrhizal fungi (AMF) abundance and aggregate mean weight diameter were higher in the perennials. No consistent significant differences were found in N₂O emissions between crops, though miscanthus tended to have the lowest emissions. Most N₂O was emitted during large events of short duration (1-3 days) that occurred after high rainfall events with high soil NO₃₋. There was a weak relationship between IPCC Tier 1 N₂O estimates and measured emissions, and the IPCC method tended to underestimate emissions. The response of N₂O to N rate was nonlinear in 2 of 3 years. Fertilizer induced emission factor (EF) increased from 0.7% at 50 kg N ha⁻¹ to 2.6% at 150 kg N ha⁻¹. Switchgrass yields increased with N inputs up to 100-150 kg N ha⁻¹, but the critical N level for maximum yields decreased each year, suggesting N was being applied in excess at higher N rates. Yield-scaled costs of production were minimized at 100 kg N ha-1 ($70.91 Mg⁻¹). Together, these results show that crop selection and fertilizer management can have large impacts on the productivity and soil GHG emissions biofuel cropping systems.

abstract: To increase the deployment of photovoltaic (PV) systems, a higher level of performance for PV modules should be sought. Soiling, or dust accumulation on the PV modules, is one of the conditions that negatively affect the performance of the PV modules by reducing the light incident onto the surface of the PV module. This thesis presents two studies that focus on investigating the soiling effect on the performance of the PV modules installed in Metro Phoenix area. The first study was conducted to investigate the optimum cleaning frequency for cleaning PV modules installed in Mesa, AZ. By monitoring the soiling loss of PV modules mounted on a mock rooftop at ASU-PRL, a detailed soiling modeling was obtained. Same setup was also used for other soiling-related investigations like studying the effect of soiling density on angle of incidence (AOI) dependence, the climatological relevance (CR) to soiling, and spatial variation of the soiling loss. During the first dry season (May to June), the daily soiling rate was found as -0.061% for 20o tilted modules. Based on the obtained soiling rate, cleaning PV modules, when the soiling is just due to dust on 20o tilted residential arrays, was found economically not justifiable. The second study focuses on evaluating the soiling loss in different locations of Metro Phoenix area of Arizona. The main goal behind the second study was to validate the daily soiling rate obtained from the mock rooftop setup in the first part of this thesis. By collaborating with local solar panel cleaning companies, soiling data for six residential systems in 5 different cities in and around Phoenix was collected, processed, and analyzed. The range of daily soiling rate in the Phoenix area was found as -0.057% to -0.085% for 13-28o tilted arrays. The soiling rate found in the first part of the thesis (-0.061%) for 20o tilted array, was validated since it falls within the range obtained from the second part of the thesis. / Dissertation/Thesis / Masters Thesis Engineering 2014

abstract: This study evaluates the potential profitability and environmental benefit available by providing renewable energy from solar- or wind-generated sources to electric vehicle drivers at public charging stations, also known as electric vehicle service equipment (EVSE), in the U.S. Past studies have shown above-average interest in renewable energy by drivers of plug-in electric vehicles (PEVs), though no study has evaluated the profitability and environmental benefit of selling renewable energy to PEV drivers at public EVSE. Through an online survey of 203 U.S.-wide PEV owners and lessees, information was collected on (1) current PEV and EVSE usage, (2) potential willingness to pay (WTP) for upgrading their charge event to renewable energy, and (3) usage of public EVSE if renewable energy was offered. The choice experiment survey method was used to avoid bias known to occur when directly asking for WTP. Sixty percent of the participants purchased their PEVs due to environmental concerns. The survey results indicate a 506% increase in the usage of public pay-per-use EVSE if renewable energy was offered and a mean WTP to upgrade to renewable energy of $0.61 per hour for alternating current (AC) Level 2 EVSE and $1.82 for Direct Current (DC) Fast Chargers (DCFC). Based on data from the 2013 second quarter (2Q) report of The EV Project, which uses the Blink public EVSE network, this usage translates directly to an annual gross income increase of 668% from the original $1.45 million to $11.1 million. Blink would see an annual cost of $16,005 per year for the acquisition of the required renewable energy as renewable energy credits (RECs). Excluding any profit seen purely from the raise in usage, $3.8 million in profits would be gained directly from the sale of renewable energy. Relative to a gasoline-powered internal combustion engine passenger vehicle, greenhouse gas (GHG) emissions are 42% less for the U.S. average blend grid electricity-powered electric vehicle and 99.997% less when wind energy is used. Powering all Blink network charge events with wind energy would reduce the annualized 2Q 2013 GHG emissions of 1,589 metric tons CO2 / yr to 125 kg CO2 / yr, which is the equivalent of removing 334 average U.S. gasoline passenger cars from the road. At the increased usage, 8,031 metric tons CO2 / yr would be prevented per year or the equivalent of the elimination of 1,691 average U.S. passenger cars. These economic and environmental benefits will increase as PEV ownership increases over time. / Dissertation/Thesis / Masters Thesis Technology 2014