The highly competitive market in the oil refining industry forces refiners look for more detailed information of both feedstocks and products to achieve the optimal economic performance. Due to stricter environmental legislations, the molecular level characterisation has been investigated by various researchers and shows promising advantages in modern refinery design and operation. Although various molecular characterisation methods have been developed, there is an unavoidable trade-off between keeping astronomical molecule details and practicality in industrial applications. In the meantime, many of these methodologies have different characteristics and different focuses according to a particular application purpose. Our aim is hence to tackle the problems of developing manageable and practical technical solutions for molecular characterisation of petroleum fractions for vary refinery processes. A pseudo-component based approach is developed within a modified MTHS (Molecular Type Homologous Series) matrix framework (Peng, 1999) to represent the molecular information of a particular refining stream. This proposed methodology incorporates both molecular type and pseudo-component information by the conjunction of homologous series and boiling points in the matrix framework. To increase the usability of this method, a 3-parameter gamma distribution function is introduced to describe the composition of each structural molecular type. Typical PIONA (paraffin, iso-paraffin, olefin, naphthene, aromatic) analysis, ratios between each homologous types and the percentage of particular carbon type are considered as well as the distillation curve and the density of a stream. More strict product specifications and environmental legislations make strong restriction to the benzene and aromatics content in gasoline products, which motivate refiners to understand, characterise and simulate gasoline catalytic reforming on molecular-level. In this work, kinetic and reactor model of naphtha catalytic reforming is developed based on the proposed MTHS method. The naphtha feedstock composition is represented by the MTHS matrix, and a kinetic network is constructed according to conversions among matrix elements. A process model proposed by Wu (2010) is employed for reforming modelling. The proposed model is then applied to a bench-scale semi-regenerative catalytic reforming unit, which contains 3 fixed-bed reactors, for validation. The influences of essential operating conditions, such as reactor inlet temperature, pressure and weight hourly space velocity (WHSV), on the product distribution and quality are explored. The developed characterisation is also applied in gasoline blending modelling. A molecular-level nonlinear gasoline blending model is developed based on proposed MTHS method with validation. Key properties such as Octane Numbers (ONs) and RVP are blended by molecular matrix elements, and the influence of molecular composition on bulk properties is obvious. A case of recipe optimisation is studied to show the applicability of the proposed method. The implementation of the developed MTHS method for catalytic reforming and gasoline blending demonstrates the compatibility when characterising different petroleum streams, and provides a common platform to simulate and optimise refining operations on the same molecular basis.

This thesis is a study conducted in collaboration with the engine performance group atHusqvarna AB. The study focuses on engine stability of smaller two stroke handheld enginesrunning on E10 (10% ethanol mixture in gasoline). The reason for the study is the new EUproposition that by 2020 all fuel must have 10 % renewable fuel content. To meet thisproposition Husqvarna has evaluated E10 and found that the engine stability of smaller twostroke engines are affected in a negative way by the fuel.The study focuses on events occurring prior to the combustion and mainly the carburetor. Theobjective for the thesis is to seek what contribution the events occurring prior to thecombustion have to the engine stability and find simple and implantable solution to improvethe stability with regards to the carburetor.The study has been conducted in three different work packages, system understanding to buildknowledge of how the carburetor operates, fault finding to seek potential attributes that canaffect the stability and fault mode analysis to seek why the attributes affect the stability.Furthermore, all the attributes found has been tested and validated on the engine to seek theircontribution to the stability.The conclusion made of the thesis is that with simple and implementable improvements of thecarburetor the engine stability could be increased with 40 %. A total of five differentattributes were found to affect the stability of the engine. Furthermore, a very detailedexplanation of how the carburetor operates and components inside the carburetor has beenestablished during the thesis.

The aim of the thesis was to analyse dependency between setting of the price level and gasoline quantum sold at a chosen distributor in the Czech Republic and in Poland. In the first part of the thesis, there are characterized price theory, tax theory, theory of state interventions, supply, demand and price elasticity of demand. In the second part, first, there is analysed whole market with fuels in both countries with their comparison. These markets have had slightly different development and they do have different market structure, because of the existence of the market leader in Poland. Second, there are analysed the data of the chosen distributor and analysed dependencies between price and quantum sold. Research showed that there is an existence of dependencies of quantum sold on both change of the absolute price and change of the relative price. These dependencies and the impact of the relative price change is more significant in the Czech Republic than in Poland.

Energy carriers, such as coal, natural gas and biomass, can be converted by Fischer-Tropsch technology into synthetic crude (syncrude). Fischer-Tropsch derived syncrude can then be refined to transportation fuels, such as motor-gasoline, jet fuel and diesel fuel. These fuels meet the same specifications as crude oil derived transportation fuels. Conventional refining technologies have to be adapted to deal with Fischer-Tropsch syncrudes, because they differ significantly from crude oil with respect to composition. Some of the key differences are the high concentration of oxygenates and olefins and absence of sulphur in Fischer-Tropsch syncrude. Imposing a crude oil refining methodology on syncrude can lead to unwieldy and expensive refineries. Yet, despite an abundance of literature of Fischer-Tropsch synthesis, there is little literature that deals with the refining of Fischer-Tropsch syncrude. The present study investigated current refining practice for both crude oil and Fischer-Tropsch syncrude in order to identify fundamental differences in their refining focus and conversion behaviour. This was followed by a critical evaluation of the compatibility of syncrudes from high temperature Fischer-Tropsch (HTFT) and low temperature Fischer-Tropsch (LTFT) synthesis with the chemistry and catalysis of various conversion processes. The conversion processes that were evaluated include isomerisation, oligomerisation, etherification, alkylation, metathesis, hydrogenation, hydroisomerisation, hydrocracking, catalytic cracking, coking, thermal cracking, catalytic reforming and dehydration. The recommendations from the technology evaluation provided the foundation for the development of Fischer-Tropsch syncrude based refinery designs. Refinery designs were developed to determine configurations that would maximise the production of on-specification motor-gasoline, jet fuel and diesel fuel respectively. It could be shown that less complex refinery designs were required to refine Fischer-Tropsch syncrude to motor-gasoline and jet fuel, than were required for crude oil refining. It was also shown that on a molecular level Fischer-Tropsch syncrude is unsuited for maximising the production of Euro-4 type diesel fuel. The present study illustrates the advantage of considering fundamentals in developing refineries specifically for Fischer-Tropsch syncrude, rather than imposing crude oil design practises on Fischer-Tropsch syncrude refinery designs. / Thesis (PhD (Chemical Engineering))--University of Pretoria, 2008. / Chemical Engineering / unrestricted

Orientador: Jarbas Jose Rodrigues Rohwedder / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T20:00:15Z (GMT). No. of bitstreams: 1 Chagas_IsmaelPereira_D.pdf: 2025832 bytes, checksum: 8e2e4a99a15486f48f4aae44dfd6f183 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho, foi desenvolvido um fotômetro NIR portátil para determinar o teor de água em álcool combustível hidratado combustível (AEHC) e o teor de etanol (Álcool etílico anidro carburente) em gasolina. Foram realizados inicialmente estudos espectroscópicos empregando um espectrofotômetro comercial para avaliar quais as melhores regiões do espectro NIR que poderiam ser empregadas para a determinação das espécies de interesse. No desenvolvimento do instrumento foram avaliados detetores baseados em um foto resistor de PbS e um fotodiodo de InGaAs. Dentre os detectores empregados o que apresentou melhores resultados foi o detector de InGaAs. Foram construídos diversos fotômetros sendo que aqueles que apresentaram as melhores performance utilizaram filtro de interferência em 1480 nm e celas cilíndricas com caminho óptico de 2 mm e 5 mm. Para o caminho óptico de 2 mm, foi utilizada como fonte de radiação uma lâmpada de 6 watts, enquanto que para a cela com 5 mm foi utilizada uma lâmpada de tungstênio de 20 watts e uma lente colimadora. Em ambos os casos, a fonte de radiação foi pulsada a uma freqüência de 25 Hz. Como transdutores de saída do instrumento foram empregados um microcontrolador PIC acoplado à um display de cristal líquido e também dois LEDs (vermelho e verde) indicando se o combustível estava dentro ou fora da especificação. O instrumento foi avaliado com amostras comerciais de álcool combustível e gasolina. Para a determinação do teor alcoólico em álcool combustível, a resposta é linear na faixa de concentração de 88 a 98% m/m, com um erro médio de 3,6 % para um total de 30 amostras analisadas, quando comparada ao seu respectivo método de referência. Na análise de amostras de gasolina foi obtida uma resposta linear para o teor de etanol entre 20 % e 30 %, com um erro médio de 3,0% para um total de 40 amostras analisadas. A ANP considera até 4% de erro médio e desta forma o instrumento classifica corretamente 100 % das amostras / Abstract: In this work a portable Near Infrared Photometer to determine the quantity of water in alcohol fuel and the quantity of ethanol in gasoline was developed. Initially, several spectroscopy analysis using a comercial spectrophotometer was made to select the best wavelenghts to determine those fuel quality parameters. The wavelengths of 1480 nm and 1920 nm were selected after preliminary study. The instrument was evaluated using two types of detectors: a PbS photoresistive detector and a InGaAs photodiode. The detector with best performance was the InGaAs photodiode. Different prototypes were built using a interference filter working in 1480 nm and path length with 2 mm and 5 mm. With the 2 mm path length was used a 6 watt tungsten lamp as radiation source and with 5 mm path length was used a 20 watts tungten lamp. This interference filter can be used to determine water in alcohol fuel and ethanol in gasoline without any changes in the instrument. The final version of the prototype showing the best results for both determinations uses a cilindric cell with 5 mm diameter and can be employed for flow or batch measurements, radiation source of a 20 watts tungsten lamp pulsed at 25 Hz and a lens to focus the infrared radiation into the detector. The output transducers of the instrument was a PIC microcontroller with a liquid crystral display and light emission diodes (LEDs) green and red. The instrument was tested using comercial fuel alcohol and gasoline samples. In the determination of water in alcohol it was obtained a linear response in the concentration range from 98 to 88 % (m/m) and in gasoline, it was 20 % to 30 %(v/v). Thirty alcohol samples were analysed showing a standard error of 3,6 % while for the gasoline, a standard error of 3,0% for a total of 40 samples analysed was found. Considering the tolerance of 4%, recommended by the National Pretoleum Agency (ANP), the instrument can classify normal and adultered samples with confidence of 100% / Doutorado / Quimica Analitica / Doutor em Quimica

The purpose of this thesis is to clarify to the reader the problem of misfuelling, which is the insertion of the wrong fuel in an engine, incompatible with the fuel inserted. Additionally, it contains research about the causes of this problem, current solutions in the market and a suggested solution according to the prior research and the findings of this thesis.

La présence de contraintes de plus en plus strictes sur les émissions de polluants on poussé les contruteurs vers l'injection directe essence (IDE), afin d'améliorer les performances et réduire la consommation de carburant et les émissions des moteurs à combustion interne. Par conséquent, de nouveaux défis sont introduits en termes d'optimisation de la combustion, en raison d'une plus complexe phénomenologie tandis que les modéles système demande des paramètres de calibration supplémentaires.Cette thèse présente le développement et la validation d'un modèle zéro-dimensionnel (0D) de combustion en IDE pour application en simulation système. Le modèle proposé détaille la physique de l'atomisation, et évaporation des gouttes, de la préparation du mélange air/carburant, de la propagation de flamme dans un mélange non-homogène ainsi que l'intéraction entre ces phénomènes.La phase liquide est discretisés en paquets groupant des gouttes de la même taille.Un modèle d'atomisation empirique basé sur la vitesse d'injection, les propriétés du carburant et les conditions thermodynamiques fournit les diamètres initiaux. Un modèle Lagrangien détaillant une dynamique de trainée/inértie, échange thermique et convection forcée décrit la pénétration liquide et l'evaporation des paquets. La formation du mélange air/carburant est décrite avec une PDF qui discretise la charge en un mécanisme de classes intéragissant les unes avec les autres et avec les paquets de gouttes. La propagation de flamme prend en compte les effets de l'hétérogéneité du mélange sur la vitesse de flamme et la formation des polluants.Le modèle proposé a été implémenté dans la plateforme Simcenter Amesim, dédiée á la modélisation de systémes multi-physiques, et intégrée dans le modèle de combustion essence CFM1D, de la librairie IFP-Engine.Des approche de modélisation de l'evaporation de carburant, de la dynamique de spray et de la formation du mélange, inspirés de la literature sur les moteurs Diesel, ont été adaptés aux conditions IDE.Le modèle a initialement été validé sur des mesures et des simulations RANS 3D réalisées avec le code IFP-C3D, d'une bombe d'injection à volume constant.Un vortex de tumble, dans un premier temps, et des variations rapides du voulume de la chambre ensuite, ont été ajoutés aux expériments numériques afin d'évaluer la réponse du modèle à l'aérodynamique dans la chambre de combustion et à des conditions thermodynamiques variables, en termes d'évaporation, développement du spray et distribution de la richesse. Des simulations d'injections dans un moteur entraîné,dont les résultats ont été comparés avec des mesures et des calculs CDF,complètent la validation du modèle avec à la fois des conditions thermodynamiques variable et de l'aérodynamique. / Future constraints on pollutant emissions pushed car manufacturers towards gasoline direct injection (GDI) technologies to improve engine performances and reduce fuel consumption and emissions. New challenges are then introduced in terms of combustion optimization due to a more complex phenomenology while system models require additional calibration parameters.This PhD work presents the development and validation of a Zero-Dimensional (0D) model of GDI combustion for system simulation. The proposed model focuses on physics of atomization and drop evaporation, fuel/air mixing, flame propagation in heterogeneous charge and mutual interaction between these phenomena.The liquid phase is discretized in parcels grouping drops of the same size. An empirical atomization model based on injection velocity, fuel characteristics and thermodynamic conditions provides initial diameters. A Lagrangian model including drag-inertia dynamics, heat-up and forced convection describes drop parcel penetration and evaporation. Fuel / air mixing is described using a discrete Probability Density Function (PDF) approach, based on constant-mixture-fraction classes interacting with each other and with the drop parcels. Flame propagation takes into account mixture heterogeneity effects on flame speed and pollutant production is modelled.The model was implemented in the Simcenter Amesim platform for multi-physical modelling and integrated in a generic Spark Ignition (SI) combustion chamber submodel, CFM1D, from the IFP-Engine library.Fuel evaporation, spray dynamics and mixture formation modelling approaches, inspired by literature on Diesel engines, were adapted to GDI operating conditions. The model was first validated on a constant-volume vessel with quiescent gas in different thermodynamic conditions by means of experiments and 3D RANS CFD simulations performed with IFP-C3D. A tumble vortex in a constant volume vessel, in a first time, and rapid variations of the vessel volume, in a second time, were then added to the numerical experiment in order to test the model response to in-cylinder flow aerodynamics and variable thermodynamic conditions, respectively, in terms of fuel evaporation, spray development and fuel/air mixing and equivalence ratio distribution. Computations of fuel injections in a motored engine complete the model validation campaign in variable thermodynamic conditions and with realistic aerodynamics and the results were compared to both experiments and CFD computations.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第22085号 / エネ博第393号 / 新制||エネ||76(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 河本 晴雄, 教授 石原 慶一, 教授 川那辺 洋 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

The process to induct air into engine cylinders, via the air inlet system and cylin-der port valves, is referred to as the "gas-exchange". Control is achieved by theturbo-charger, the intake throttle plate and the variable valve timing (VVT) sys-tem. These actuation systems traditionally use separate control with indepen-dent SISO feedback. There are however physical couplings that affect the con-trol performance. This thesis work looks at MPC control methods for a robustcontrol strategy. MPC methods are typically used for systems with slow dynam-ics, due to computational limits. But new advances in CPU performance shouldallow for real-time implementations for engine control. / <p>Redan framlagt exjobbet</p>

Gasoline compression ignition (GCI) engines show promise in meeting stringent new environmental regulations, as they are characterized by high efficiency and low emissions. Simulations using chemical kinetic models provide an important platform for investigating the behaviors of the fuels inside these engines. However, because real fuels are complex, simulations require surrogate mixtures of small numbers of species that can replicate the properties of real fuels. Accordingly, the development of high fidelity, well-validated kinetic models for surrogates is critical in order to accurately replicate the combustion chemistry of different fuels under engine-related conditions. This work focuses on the development of combustion kinetic models to better understand gasoline fuel combustion in GCI engines. An updated iso-octane detailed kinetic model was developed based on new thermodynamic group values and recently evaluated rate coefficients from literature. The model was validated against a wide range of experimental data and conditions. The iso-octane model was further used in 0D simulations for a homogeneous charge compression ignition (HCCI) engine. The results showed that the low-temperature heat release in engines increases with engine boosting when the addition of alky radicals to molecular oxygen is more favored. Ethanol addition was also found to act as a radical sink which inhibits the radical pool formation and results in lower reactivity. Although detailed models provide clarification of the combustion chemistry, their high computational cost impedes their utilization in 3-D engine simulations. Hence, a reduced model for toluene primary reference fuels was developed and validated against ignition delay time and flame speed experiments from literature. The model was then used in numerically investigating the effects of the fuel’s physical properties using hollow-cone and multi-hole injectors in a partially premixed compression ignition (PPCI) engine. It was concluded that the effects of physical properties are evident in multi-hole injection cases, which is attributable to the differences in mixture stratification. Finally, reduced models for multi-components surrogates for three full-blend fuels (light naphtha-Haltermann straight-run naphtha and GCI fuels) were developed. The models were validated against ignition delay time experiments from the literature and tested in 3D engine simulations.