The labelling of methyl tertiary butyl ether (MTBE), an oxygenate additive used extensively in gasoline blending, as an environmentally harmful chemical has led to the banning and subsequent phasing-out of this additive in California (USA). In response, the global petroleum industry is currently considering replacement strategies, which include the use of tertiary amyl methyl ether (TAME) or ethanol. Subsequently, SASOL (South African Coal and Oil Limited), a local petrochemical company, in its capacity as an environmentally responsible player in the global petroleum and aligned chemical markets, has commissioned this investigation into the environmental fate of the fuel oxygenates: TAME, ethanol and MTBE. In order to evaluate the environmental fate of the oxygenates, this dissertation has formed a three-tiered approach, using MTBE as a benchmark. The first tier assessed the general fate behaviour of the oxygenates using an evaluative model. A generic evaluative model, developed by Mackay et al. (l996a), called the Equilibrium Criterion (EQc) model was used for this purpose. This fugacity based multimedia model showed MTBE and TAME to have similar affinities for the water compartment. Ethanol was demonstrated to have a pre-disposition for the air compartment. Parameterisation of the EQC model to South African conditions resulted in the development of ChemSA, which reiterated the EQC findings. The second tier quantified the persistence (P), bioaccumulation (B) and long-range transport (LRT) potential of the additives. This tier also included a brief toxicity (T) review. MTBE and ethanol were demonstrated to be persistent and non-persistent, respectively, according to three threshold limit protocols (Convention on the Long Range Trans-boundary Air Pollution Persistent Organic Chemical Protocol; the United Nations Environment Programme Global Initiative; and the Track 1 criteria as defined by the Canadian Toxic Substances Management Policy, as referred to by the Canadian Environmental Protection Act 1999). These protocols were not unanimous in the persistence classification of TAME. Further investigation of persistence was conducted using a persistence and long-range transport multimedia model, called TaPL3, developed by Webster et al. (1998) and extended by Beyer et al. (2000). TaPL3 reiterated the conclusions drawn from the threshold limit protocols, indicating that TAME's classification worsened from non-persistent to persistent on moving from an air emission to a water emission scenario. This served to emphasise the negative water compartment affinity associated with TAME. Using classification intervals defined by Beyer et al. (2000), TaPL3 demonstrated that the long-range transport potential of the oxygenates increased in the order of TAME, ethanol and MTBE; however, it was concluded that none of the oxygenates were expected to pose a serious long-range transport threat. Bioaccumulation was not expected to be a pertinent environmental hazard. As expected, the oxygenates were dismissed as potential bioaccumulators by the first level of a screening method developed by Mackay and Fraser (2000); as well as by the threshold limit protocols listed above. Simulation of biomagnification, using an equilibrium food chain model developed by Thomann (1989), demonstrated that none of the oxygenates posed a biomagnification threat. A review of toxicity data confirmed that none of the three oxygenates are considered particularly toxic. LDso values indicated the following order of increasing toxicity: ethanol, MTBE and TAME. The third tier focussed on oxygenate aqueous behaviour. A simple equilibrium groundwater model was used to analyse the mobility of the oxygenates in groundwater. TAME was found to be 21 % less mobile than MTBE. Ethanol was shown to be very mobile; however, the applicability of the equilibrium model to this biodegradable alcohol was limited. An analysis of liquid-liquid equilibria comprised of oxygenate, water and a fuel substitution chemical was performed to investigate fuel-aqueous phase partitioning and the co-solvency effects of the oxygenates. Ethanol was shown to partition appreciably into an associated water phase from a fuel-phase. Moreover, this alcohol was shown to act as a co-solvent drawing fuel chemicals into the water phase. MTBE was found to partition sparingly into the water phase from a fuel-phase, with TAME partitioning less than MTBE. Neither ether was shown to act as a co-solvent. It was concluded that TAME and ethanol pose less of a burden to the environment than MTBE. Ethanol was assessed to be environmentally benign; however, it was concluded that ethanol's air compartment affinity and the extent of its co-influence on secondary solutes justified the need for further investigation before its adoption as a fuel additive. This project showed sufficient variation in the environmental behaviour of TAME and MTBE to justify the abandonment of the axiom that MTBE and TAME behave similarly in the environment. However, as MTBE is a significant water pollutant, and TAME has been shown to share a similar water affinity, it is cautiously recommended that the assumption of environmental similarity be discarded, except for the water compartment. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2002.

Although concentrated solar power can be used to produce power using traditional electricity generation, energy storage has become a problem due to the intermittent supply of solar energy. By using solar energy in chemical production processes, the solar energy can be stored in a useful chemical product. The purpose of this thesis will be to examine the possibilities of a new solar chemical cycle the produces iron and ethylene from hematite (a form of iron oxide) and ethane using concentrated solar power. These two products are important stepping stones in the production of steel and polymers. This process could allow for the current process of steel production to move away from processes using coal and towards a more sustainable process using the hydrogen formed from the ethane cracking process and solar energy. The thesis will include: (1) the development of a new solar powered iron and ethylene combined cycle, (2) a feasibility study of a Concentrated Solar Heat Supply System (CSHSS) being developed at Georgia Tech, and (3) an assessment of the proposed cycle. The assessment will include an estimate of production including a thermodynamic ASPEN model, assessment of research to realize actualization of the theoretical cycle, an exergy analysis, and a heat exchanger analysis for the exchange of heat between the CSHSS and the chemical process.

Over the past few decades, a growing interest in the thermal conversion of alternative fuels such as biomass and waste-derived fuels has been observed among the energy-producing companies. Apart from meeting the increasing demand for sustainable heat and power production, other advantages such as reducing global warming and ameliorating landfilling issues have been identified. Among the available thermal conversion technologies, combustion in grate-fired furnaces is by far the most common mode of fuel conversion. In recent years, Fluidized-Bed (FB) technologies have grown to become one of the most suitable technologies for combustion and gasification of biomass and waste-derived fuels.In spite of the benefits, however, some difficulties are attributed to the thermal conversion of the alternative fuels. Ash-related issues could be a potential problem, as low-grade fuels may include considerable concentrations of ash-forming elements such as K, Na, S, Ca, Mg, P, Si and Cl. These elements undergo many undesirable chemical and physical transformations during the thermal conversion, and often cause operational problems such as deposition-related issues, slag formation in furnaces, corrosion of the heat transfer surfaces, and bed agglomeration of the fluidized-beds. Ash-related problems in the utility boilers are a major concern that may result in decreased efficiency, unscheduled outages, equipment failures, increased cleaning and high maintenance costs.This thesis investigated the ash behavior and ash-related problems in two different FB conversion systems: a Bubbling Fluidized-Bed (BFB) boiler combusting solid waste, and a Dual Fluidized-Bed (DFB) gasifier using biomass as feedstock. Full-scale measurements, chemical analysis of fuel and ash, as well as thermodynamic equilibrium modeling have been carried out for the BFB boiler (Papers I-IV), to investigate the impact of reduced-bed temperature (RBT) and also co-combustion of animal waste (AW) on the ash transformation behavior and the extent of ash-related issues in the boiler. For the DFB gasifier (Paper V), a thermodynamic equilibrium model was developed to assess the risk of bed agglomeration when forest residues are used as feedstock.The experimental results showed that the RBT and AW co-combustion could decrease or even resolve the ash-related issues in the BFB boiler, resulting in a lower deposit-growth rate in the superheater region, eliminating agglomerates, and a less corrosive deposit (in RBT case). Thermodynamic equilibrium modeling of the BFB boiler gave a better understanding of the ash transformation behavior, and also proved to be a reliable tool for predicting the risk of bed agglomeration and fouling. The modeling of the DFB gasifier indicated a low risk of bed agglomeration using the forest residues as feedstock and olivine as bed material, which was in good agreement following the observations in a full-scale DFB gasifier.

Miroslav Ottomansky Legal regulation of protection against air pollution from mobile sources The goal of this thesis is to map tools used for legal regulations of mobile pollution sources. Thesis focuses on problematic regulation of motor vehicles' pollution in Czech Republic, however it also outlines basic legal adjustements related to other mobile pollution sources. Thesis starts with basic introduction to this problematic followed by overview of international legal regulations and main conceptional tools used for legal regulations in European Union. In the chapter dedicated to the principles of european law in terms of regulation of mobile sources' pollution thesis tries to research how are those regulations already being applied to specific legal norms. One chapter is dedicated to protection of rights for convenient environment and their prosecution. In the next part of the thesis the normative regulations within emission standarts, approval of types, requirements for fuel quality and control of emissions of motor vehicles are examined. In the last chapter the new legal adjustment of mobile sources' pollution named in the law of enviroment protection is briefly explained in context with increasing number of problems with regulation of road traffic in cities. Key words: air pollution from mobile sources,...

Afin de répondre aux demandes des industriels de nouveaux matériaux poreux sont testés pour de nouvelles applications ou pour améliorer les procédés existants. Les adsorbants de types Metal Organic Frameworks(MOFs) ont des structures construites à partir d'unités inorganiques reliées entre elles par des ligands organiques. La possibilité de varier ces deux entités, offre une grande diversité de structures avec des cavités de tailles contrôlées. L'objectif de cette thèse a été d'évaluer les performances des MOFs pour l'adsorption de composés organiques et de comprendre les mécanismes d'adsorption. Les deux problématiques sélectionnées sont d'intérêt pour l'industrie pétrochimique. La séparation du para-xylène des autres isomères du xylène et de l'éthylbenzene, permets de répondre à la demande de matière première pour la synthèse du polytéréphtalate d'éthylène. L'adsorption des composés azotés et soufrés (teneur fixée par des législations), permets la purification de carburants. Notre étude thermodynamique est basée sur la réalisation d'isothermes d'adsorption et la détermination d'enthalpies d'adsorption par microcalorimétrie en phase liquide. L'adsorption des vapeurs des xylènes purs a été étudiée pour comprendre l'effet du solvant. Une grande variété de comportement a été observée selon les structures des MOFs. Nous avons par exemple mis en évidence l'effet de l'empilement moléculaire des isomères du xylène sur la sélectivité des MOFs. Nous avons démontré que la flexibilité des MOFs intervient sur les interactions au cours de l'adsorption des xylènes. Nous avons mis en évidence une sélectivité des MOFs possédant un centre métallique insaturé en faveur des composés azotés / In order to meet the industrials requirements, new porous materials are tested for new applications or to improve existing processes. The Metal Organic Frameworks (MOFs) are hybrids crystalline compounds made up of clusters (or chains) of metal ions coordinated by organic linkers to form three dimensional structures. The ability to vary these two entities offers to MOFs a wide variety of organized structure with pore sizes controlled. The aim of this thesis was to evaluate the MOF performances for the adsorption of organic compounds and also understand the related adsorption mechanism. The two selected issues are of interest for the petrochemical industry. The para-xylène separation from the other xylene isomers (ortho, meta) and ethylbenzene, allows to meet the demand for raw materials in the polyethylene terephthalate (PET) synthesis. The nitrogen and sulphur compounds adsorption allows the purification of fuels (sulphur content set by legislation). We present a thermodynamic study of adsorption from solution based on the determination of adsorption isotherms by depletion method and adsorption enthalpies by microcalorimetry. The pure xylenes vapour adsorption was also studied to understand the solvent effect. A wide variety of behaviour has been observed depending on MOF structures. For example we demonstrated the effect of xylene isomers molecular packing on MOF selectivity. Furthermore we have shown that the MOF structure flexibility influence the interactions involved during xylene isomers adsorption. We also demonstrated that MOF with unsaturated metallic centres present selectivity for nitrogen compounds (Lewis acid/base).

This paper analyses the purchase and operation of vehicles on compressed natural gas. It contains a definition of Compressed Natural Gas (CNG) and discusses the various phases of its use in transport. It indicates the differences of this alternative fuel compared to traditional fuel such as gasoline or diesel. Then it focuses on the main reasons to support the use of compressed natural gas transport and talks about the legislation which has a major role in the development of alternative fuels. Then it specifies the disadvantages which can be associated with its use in transport. The last section includes an analysis on the specific example of the RWE CZ Group, which compares the different costs for compressed natural gas vehicles and vehicles which run on conventional fuel. Specifically the cost per kilometer of vehicle, CO2 emission and purchase price are given for comparison.

<div>High speed laser diagnostics are performed in two vastly differing swirl combustors at conditions relevant for industrial gas turbines. This high quality data can not only be used to elucidate key features of the flow field but also for validation of computational models simulating turbulence, chemistry, and their interactions. The first combustor is a piloted lean premixed prevaporized arrangement common in aviation applications. Fueling parameters are varied and sensitivity towards the pilot flame is observed. Conditioning to the stagnation line demonstrates increased fluctuations of shear and rotation in the inner shear layer when the pilot fueling is reduced.</div><div><br></div><div>The second flame has a simpler configuration with a single swirler and combusting natural gas. Thermoacoustic instability coupled to a helical precessing vortex core is found at certain conditions. Sparse Dynamic Mode Decomposition and phase averaging is applied to the velocity fields to create a three dimensional reconstruction of the helical vortex core in a non-precessing reference frame. Heat release is found to be correlated to the interaction strength of the central recirculation bubble and the helical vortex core. </div><div><br></div><div> </div><div>Finally, intermittent phenomena within a thermoacoustic instability are examined. The most prominent deviation is that the flame is observed to randomly lift and reattach. In addition, a convolutional neural network is employed to extract the morphology from otherwise qualitative OH species imaging. The average characteristics of the lifted and attached flame are compared and dramatic differences are found. All of the flow structures have been altered such as the precessing vortex core being greatly intensified during flame lift-off. Evaluating the average events before flame lift-off revealed the importance of conditions at the combustor inlet. However, evidence for a future reattachment event was only found with a less spatially confined perspective. In addition, transition to lift-off was very sudden while reattachment was far slower.</div>

With increasing recognition that reducing carbon emissions from energy in the UK will make a significant contribution to the mitigation of anthropogenic climate change, and with carbon budgets forged following the Climate Change Act 2005 looking unlikely to be met, it is clear that sectoral changes are required to catalyse the decarbonisation process. Alongside the need for this industry to be at the forefront of decarbonisation, the energy sector needs to diversify and employ more women, Black and Minority Ethnic (BAME), LGBT and disabled people, as well as those from different social classes and varied educational backgrounds. In short, the energy industry in the UK presently has a diversity issue that transcends being an image problem; it is hampering progress. This masters’ thesis explores how the dual aims of decarbonisation and diversifying the workforce can aid one another, and the extent to which greater diversity within the energy sector could actually be the key to decarbonisation. Using transcripts from the interviews I conducted with eight individuals, as well as meta- analysis of existing data that examines the impacts of diversity in various industries, the ways in which greater diversity in the energy sector has the potential to be positive for decarbonisation are explored. Further, this paper also examines barriers to diversity, proposing a series of recommendations for industry and policy makers in order to create an energy sector that is more diverse. These recommendations can be found in the next steps section of the paper, which aims to provide guidance for those wishing to make the composition of their organisation more representative of wider society.

O IPEN/CNEN-SP fabrica combustíveis para uso no seu reator nuclear de pesquisas, o IEA-R1. Para qualificar os seus combustíveis tem que comprovar o bom desempenho destes sob irradiação. Como o Brasil não possui reator nuclear de pesquisa com altos fluxos de nêutrons ou células quentes apropriadas para a realização de exames pós-irradiação de combustíveis nucleares, o IPEN/CNEN-SP conduziu um programa de qualificação operacional de elementos combustíveis empregando compostos de urânio já internacionalmente testados sob irradiação e qualificados para uso em reatores de pesquisas, obtendo experiência nas etapas de desenvolvimento tecnológico de fabricação de placas combustíveis, irradiação e ensaios não destrutivos pós-irradiação. Foram fabricados e irradiados diretamente no núcleo do IEA-R1, com sucesso, elementos combustíveis contendo dispersões com baixas frações volumétricas de combustível. Entretanto, existem planos no IPEN/CNEN-SP para aumentar a densidade de urânio dos seus combustíveis. O objetivo deste trabalho de tese consistiu no estudo e proposição de aplicação de um conjunto de métodos não destrutivos para a qualificação dos combustíveis a dispersão de U3O8-Al e U3Si2-Al com alta densidade de urânio fabricados no IPEN/CNEN-SP. Para tanto, foram considerados os recursos de irradiação e a aplicação, na piscina do reator IEA-R1, de métodos não destrutivos disponíveis na Instituição. A proposta consiste em especificar, fabricar e irradiar miniplacas combustíveis, nas densidades máximas já qualificadas internacionalmente e efetuar acompanhamento das condições gerais das mesmas, ao longo do período de irradiação, por meio de métodos não destrutivos na piscina do reator. Além dos métodos de inspeção visual e de sipping já empregados na Instituição, foi concluída a infraestrutura para realização de ensaios dimensionais sub-aquáticos para a avaliação do inchamento das miniplacas combustíveis irradiadas. As análises dos resultados darão subsídios para avaliar e decidir a continuidade ou não das irradiações das miniplacas, até que sejam alcançadas as queimas estipuladas para os testes de irradiação no IEA-R1. / IPEN/CNEN-SP manufactures fuels to be used in its nuclear research reactor the IEA-R1. To qualify those fuels, it is necessary to check if they have a good performance under irradiation. As Brazil doesnt have nuclear research reactors with high neutron fluxes, or suitable hot cells for carrying out post-irradiation examination of nuclear fuels, IPEN/CNEN-SP has conducted a fuel qualification program based on the use of uranium compounds, internationally tested and qualified to be used in research reactors, and has gotten experience in the technological development stages for the manufacturing of fuel plates, irradiation and non-destructive post-irradiation testing. Fuel elements containing low volume fractions of fuel in the dispersion were manufactured and irradiated successfully directly in the core of the IEA-R1. However, there are plans to increase the uranium density of these fuels. The objective of this thesis work was to study and to propose a set of non-destructive methods to qualify the dispersions fuels U3O8-Al e U3Si2-Al with high uranium density produced at IPEN/CNEN-SP. For that, the irradiation resources in the IEA-R1, and the application of non-destructive methods in the reactor pool available in the Institution were considered. The proposal is to specify, manufacture and irradiate fuel miniplates in IEA-R1 at the maximum densities, qualified internationally, and to monitor their general conditions during the period of irradiation, using non-destructive methods in the reactor pool. In addition to the non-destructives visual inspection and sipping methods, already used at the Institution, the infrastructure for dimensional sub-aquatic testing to evaluate the swelling of irradiated fuel miniplates was completed. The analyses of the results will provide means to assess and decide whether or not to continue with the irradiation of miniplates, until the desired burnup for the irradiation tests at IEA-R1 are reached.

O processamento de petróleo e seus derivados é analisado pela aplicação combinada e sistemática da Primeira e da Segunda Lei da Termodinâmica, análise exergética, permitindo a localização dos principais processos destruidores da capacidade de realização de trabalho ao longo da cadeia de processamento. Após a localização das irreversibilidades, diversas opções para melhoria dos processos são avaliadas. A exergia consumida nos processos é dividida em renovável e não renovável e posteriormente repartida, junto com as respectivas emissões de CO2, entre as diversas correntes de cada unidade de processamento. Para uma repartição racional dos fluxos exergéticos e de CO2, a análise exergoeconômica foi utilizada. Um sistema, que permite interações cíclicas entre a cadeia produtiva dos principais combustíveis utilizados no Brasil e a produção de eletricidade, foi elaborado a fim de permitir uma comparação entre os diversos combustíveis levando em consideração toda a cadeia produtiva. Esta comparação está fundamentada no consumo de exergia renovável e não renovável e nas emissões de CO2. Pode-se concluir que o coque de petróleo é o combustível que mais emite CO2, em seguida, encontram-se o carvão e a gasolina. O diesel hidrotratado vem após a gasolina, devido principalmente ao consumo de hidrogênio pelo hidrotratamento. Embora o diesel convencional emita mais SOx e NOx, este diesel exige menos exergia não renovável e emite menos CO2 que o diesel hidrotratado. O hidrogênio, se produzido da forma convencional (reforma a vapor de hidrocarbonetos leves), é o combustível mais intenso em exergia não renovável e com emissão de CO2 próxima ao valor da gasolina e maior que o valor obtido para o diesel convencional. O etanol se mostra uma boa alternativa ao uso dos derivados de petróleo, mesmo considerando configurações típicas para as usinas sucroalcooleiras. / The oil processing is analyzed by the combined and systematic application of the First and Second Laws of Thermodynamics, exergy analysis, allowing the location of the processes responsable for the main destructions of work capability along the processing chain. After the location of irreversibilities, several options for improving processes efficiency are evaluated. The exergy consumed in the processes is divided into renewable and non-renewable and then distributed, along with their CO2 emissions, among the various currents of each processing unit. For a rational distribution of the exergy and CO2 flows, exergoeconomy analysis takes place. A system that allows cyclical interactions between the productive chain of the main fuels used in Brazil and electricity production, is designed to allow the comparison among different fuels taking into account the entire production chain. This comparison is based on renewable and non-renewable exergy consumption and CO2 emissions. It can be concluded that the petroleum coke is the fuel that emits more CO2 followed by coal and gasoline. The hydrotreated diesel comes after gasoline, mainly due to the consumption of hydrogen for hydrotreating. Although conventional diesel emit more NOx and SOx, this diesel requires less non-renewable exergy and emits less CO2 than hydrotreated diesel. Hydrogen, if produced in the conventional way (steam reforming of light hydrocarbons) is the fuel most intense in nonrenewable exergy consumption and has CO2 emission near the value of gasoline and higher than the value obtained for conventional diesel. Ethanol is a good alternative to the use of petroleum derived fuels, even considering typical configurations for sugarcane mills.