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Internal combustion engines (ICEs) are essential for the welfare of today’s human civilization yet they contribute to almost 10% of the global CO2 emissions. Reducing the carbon footprint of the ICEs can be achieved by either increasing the engine efficiency to reduce fuel consumption or the utilization of carbon-neutral fuels. This dissertation aims to investigate the effect of the oxidizer composition on the efficiency and performance of the homogenous charge compression ignition (HCCI) engine. It also aims to study the behavior of hydrogen in HCCI engines. The experiments are conducted using a Cooperative Fuel Research (CFR) engine. The study also involves using chemical kinetics simulations to estimate the ignition delay time of hydrogen which is relevant to the HCCI mode of combustion. The results suggest that the specific heat ratio of the oxidizer does not significantly affect the HCCI engine efficiency. On the fuel side, hydrogen showed high sensitivity to engine running conditions due to the lack of negative temperature coefficient (NTC).

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No description available.

No description available.

Carbon capture and storage (CCS) and a point of electricity generation is a promising option for mitigating greenhouse gas emissions. One issue with respect to CCS is the design of carbon dioxide transport, storage and injection system. This dissertation develops a model, OptimaCCS, that combines economic and spatial optimization for the integration of CCS transport, storage and injection infrastructure to minimize costs. The model solves for the lowest-cost set of pipeline routes and storage/injection sites that connect CO2 sources to the storage. It factors in pipeline costs, site-specific storage costs, and pipeline routes considerations involving existing right of ways and land use. It also considers cost reductions resulting from networking the pipelines segment from the plants into trunk lines that lead to the storage sites. OptimaCCS is demonstrated for a system involving carbon capture at 14 Texas coal-fired power plants and three potential deep-saline aquifer sequestration sites. In turn OptimaCCS generates 1) a cost-effective CCS pipeline network for transporting CO2 from all the power plants to the possible storage sites, and 2) an estimate of the costs associated with the CO2 transport and storage. It is used to examine variations in the configuration of the pipeline network depending on differences in storage site-specific injection costs. These results highlight how various levels of cooperation by CO2 emitters and difference in injection costs among possible storage sites can affect the most cost-effective arrangement for deploying CCS infrastructure. This study also analyzes CCS deployment under the features in a piece of legislation the draft of American Power Act (APA) - that was proposed in 2010 which contained a goal of CCS capacity for emissions from 72 Gigawatt (GW) by 2034. A model was developed that simulates CCS deployment while considering different combinations of carbon price trajectories, technology progress, and assumed auction prices. The model shows that the deployment rate of CCS technology under APA is affected by the available bonus allowances, carbon price trajectory, CCS incentive, technological adaptation, and auction process. Furthermore it demonstrates that the 72GW objective can only be achieved in a rapid deployment scenario with quick learning-by-doing and high carbon price starting at 25 dollars in 2013 with a 5 percent annual increase. Furthermore under the slow and moderate deployment scenarios CCS capacity falls short of achieving the 72 GW objective.

Submitted by KELY REGINA MAXIMO VIEIRA null (kely_eng@hotmail.com) on 2016-04-05T18:09:58Z No. of bitstreams: 1 Dissertação de mestrado Kely UNESP_FEG.pdf: 6192545 bytes, checksum: 59d853e87efba339ac6bea6aeab6f11d (MD5) / Rejected by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija estas informações e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2016-04-07T20:05:13Z (GMT) / Submitted by KELY REGINA MAXIMO VIEIRA null (kely_eng@hotmail.com) on 2016-04-07T20:34:23Z No. of bitstreams: 1 Dissertação Kely UNESP FEG.pdf: 6196946 bytes, checksum: bf09868facff4fd8869dde5f2fcde047 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-08T16:21:52Z (GMT) No. of bitstreams: 1 vieira_krm_me_guara.pdf: 6196946 bytes, checksum: bf09868facff4fd8869dde5f2fcde047 (MD5) / Made available in DSpace on 2016-04-08T16:21:52Z (GMT). No. of bitstreams: 1 vieira_krm_me_guara.pdf: 6196946 bytes, checksum: bf09868facff4fd8869dde5f2fcde047 (MD5) Previous issue date: 2016-03-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Nesta dissertação, investiga-se a reação de dissolução ácida de rochas silicatos brasileiras visando a aplicação em um processo de captura e sequestro de carbono denominado por Carbonatação Mineral. Na carbonatação mineral pela rota indireta utiliza-se ácidos, bases ou sais de amônia para a extração do magnésio, principalmente, presente na rocha silicato a fim de a formar carbonatos estáveis. Destaca-se que a etapa de dissolução ácida é uma fase limitante para o processo de carbonatação mineral, principalmente por apresentar baixa taxa de reação. O objetivo deste trabalho é utilizar o ácido clorídrico (HCl) e dois serpentinitos oriundos do estado de Goiás e Minas Gerais para avaliar o processo de dissolução ácida. Os serpentinitos foram preparados, selecionados e caracterizados para determinar a composição elementar. Aplicou-se o planejamento experimental e arranjo L9 de Taguchi na avaliação dos fatores que influenciam o processo de dissolução, tais como, temperatura do processo, concentração do HCl, tamanho médio das partículas da matéria prima e excesso de ácido. Os 9 ensaios previstos na matriz de planejamento para cada serpentinito foram executados de forma aleatória e em duplicata. Os produtos finais, resíduo sólido retido no papel filtro e solução contendo os elementos de interesse, foram analisados obtendo-se a composição elementar das soluções. Considerando-se os testes previstos na matriz de planejamento, a condição de melhor ajuste para extração de Mg foi utilizando-se a granulometria média de 69 µm, temperatura de 70°C, HCl 2 M com quatro vezes a quantidade estequiométrica. Nas soluções foram obtidas as concentrações de 29 % e 76 % de Mg para as amostras de serpentinito de Minas Gerais e de Goiás, respectivamente. Foram também avaliadas as melhores condições para extração de Fe e Ca e menor extração de Si, uma vez que o Si diminui a conversão no processo. Na análise estatística verificou-se que para a amostra de Minas Gerais todos os fatores apresentaram significância. No caso da a amostra de Goiás a temperatura no nível alto (70°C) apresentou maior significância. / In this dissertation, acid dissolution reaction of Brazilian silicate rocks was investigated aiming the implementation in a Carbon Capture and Storage process named Mineral Carbonation. In the mineral carbonation by indirect route, acids, bases or salts of ammonia are used for magnesium extraction, mainly, present in the silicate rock in order to form stable carbonates. It is noteworthy that the acid dissolution step is a limiting step in the process of mineral carbonation, mainly because of its low reaction rate. The objective of this study was to use hydrochloric acid (HCl) and two serpentinites from Goiás and Minas Gerais states to evaluate the acid dissolution process. The serpentinites were prepared, selected, and characterized to determine the elemental composition. The L9 experimental design and Taguchi arrangement were applied to evaluate the factors that influence in the dissolution process, such as process temperature, HCl concentration, average particle size of material and acid excess. The nine tests prescribed in planning matrix for each serpentinite were performed at random and in duplicate. The end products, solid residue retained on the filter paper and the solution containing the elements of interest were analyzed obtaining the elemental composition of the solutions. Considering the prevised tests on planning matrix, the best adjust condition for Mg extraction was using the average particle size of 69 µm temperature of 70°C, 2 M HCl with four times the stoichiometric amount. In the solutions, the concentrations obtained were 29 % and 76 % Mg for samples of serpentinite from Minas Gerais and Goiás, respectively. The best conditions for the extraction of Fe and Ca and lower extraction of Si were evaluated, since Si decreases the conversion in the process. In the statistical analysis was found that in Minas Gerais sample all factors were significant. In the case of Goiás sample, the temperature at the high level (70°C) showed greater significance.

Offshore oil platforms are used for the exploitation and production of hydrocarbons and consist of a processing plant and a utility plant. The oil and gas industry operations are energy-intensive and, in the case of offshore platforms, the need to decrease energy consumption and reduce CO2 emissions has increased. In the oil and gas industry, the ISO 50001 standard promotes the implementation of energy management systems and proposes indicators based on energy. Interestingly, after several decades of knowledge of the concept of exergy, this has not been formally implemented in the programs and strategies of the oil and gas industry organizations. In this research, the implementation of the exergy method and the carbon capture and storage strategy for the assessment of the performance of a floating, production and storage offloading units FPSO is proposed. FPSO platforms and their processing and utility plants may have different configurations depending on, among others, the reservoir characteristics and production requirements. The possible configurations can therefore be numerous. In this sense, some operation scenarios based on different well-fluid compositions and operation modes are studied. The platform models are developed and simulated using the software Aspen HYSYS®. Results show that, on average, the reduction of 88.8% in CO2 emissions is penalized with a reduction in exergy efficiency of 1.7 points. Further, results allow a better understanding of exergy and environmental performance of the FPSO. / Plataformas de petróleo offshore são utilizadas para a exploração e produção de hidrocarbonetos e consistem em uma planta de processamento e uma planta de utilidade. As operações da indústria de petróleo e gás são de energia intensiva e, no caso de plataformas offshore, é necessário cada vez mais diminuir o consumo de energia e reduzir as emissões de CO2. Na indústria de petróleo e gás, a norma ISO 50001 promove a implementação de sistemas de gestão de energia e propõe indicadores baseados em energia. Entretanto, após várias décadas de conhecimento do conceito de exergia, este não foi formalmente implementado nos programas e estratégias das organizações da indústria de petróleo e gás. Neste trabalho, propõe-se a implementação da análise exergética e a estratégia de captura e armazenamento de carbono para a avaliação do desempenho de unidades flutuantes, de produção, de armazenamento e transferência FPSO. As plataformas FPSO e suas plantas de processamento e utilidade podem ter diferentes configurações dependendo, entre outras, das características do reservatório e dos requisitos de produção. As configurações possíveis podem, portanto, ser numerosas. Neste sentido, são estudados alguns cenários de operação baseados em diferentes composições dos fluidos do poço e em três modos de operação. Os modelos de plataforma são desenvolvidos e simulados usando o software Aspen HYSYS®. Os resultados mostram que, em média, a redução de 88,8% nas emissões de CO2 é penalizada com uma redução da eficiência exergética de 1,7 pontos. Além disso, os resultados permitem uma melhor compreensão da exergia e desempenho ambiental do FPSO.

The thermodynamic properties of CO2-mixtures are essential for the design and operation of CO2 Capture and Storage (CCS) systems. A better understanding of the thermodynamic properties of CO2 mixtures could provide a scientific basis to define a proper guideline of CO2 purity and impure components for the CCS processes according to technical, safety and environmental requirements. However the available accurate experimental data cannot cover the whole operation conditions of CCS processes. In order to overcome the shortage of experimental data, theoretical estimation and modelling are used as a supplemental approach.   In this thesis, the available experimental data on the thermodynamic properties of CO2 mixtures were first collected, and their applicability and gaps for theoretical model verification and calibration were also determined according to the required thermodynamic properties and operation conditions of CCS. Then in order to provide recommendations concerning calculation methods for engineering design of CCS, totally eight equations of state (EOS) were evaluated for the calculations about vapour liquid equilibrium (VLE) and density of CO2-mixtures, including N2, O2, SO2, Ar, H2S and CH4.   With the identified equations of state, the preliminary assessment of impurity impacts was further conducted regarding the thermodynamic properties of CO2-mixtures and different processes involved in CCS system. Results show that the increment of the mole fraction of non-condensable gases would make purification, compression and condensation more difficult. Comparatively N2 can be separated more easily from the CO2-mixtures than O2 and Ar. And a lower CO2 recovery rate is expected for the physical separation of CO2/N2 under the same separation conditions. In addition, the evaluations about the acceptable concentration of non-condensable impurities show that the transport conditions in vessels are more sensitive to the non-condensable impurities and it requires very low concentration of non-condensable impurities in order to avoid two-phase problems.   Meanwhile, the performances of evaporative gas turbine integrated with different CO2 capture technologies were investigated from both technical and economical aspects. It is concluded that the evaporative gas turbine (EvGT) cycle with chemical absorption capture has a smaller penalty on electrical efficiency, while a lower CO2 capture ratio than the EvGT cycle with O2/CO2 recycle combustion capture. Therefore, although EvGT + chemical absorption has a higher annual cost, it has a lower cost of electricity because of its higher efficiency. However considering its lower CO2 capture ratio, EvGT + chemical absorption has a higher cost to avoid 1 ton CO2. In addition the efficiency of EvGT + chemical absorption can be increased by optimizing Water/Air ratio, increasing the operating pressure of stripper and adding a flue gas condenser condensing out the excessive water. / QC 20100819