Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Glass kerosene lamps --- History. --- Lamps --- History

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

If climate change is evident, society’s current ecological transition is also apparent. Renewable energy sources utilisation is paramount to mitigate the anthropogenic environmental impact. However, they present significant drawbacks, including primarily their variability. It implies the necessity to store them in the medium and long term to address this problem, which is possible through the Power-to-X technology. This work specifically focuses on the production of e-kerosene through the low-temperature cobalt-based Fischer-Tropsch synthesis. There are various kinetics in the literature describing this reaction. The overall idea behind this master’s thesis is to identify the best kinetic
model to be implemented in a reactor model. Ultimately, it will help to understand the interactions
between the reaction and the rest of the process.
In this work, the kinetics developed by Ma et al. (2014a,b) are specifically studied. Compared to
more classical models, it includes a positive kinetic effect induced by water. A reactor model is developed in Aspen Custom Modeler® in which the kinetics are considered. The reaction stoichiometry is developed following the Anderson-Schulz-Flory theory by accounting for the methane deviation
from this ideal model.
The implementation of these kinetics and stoichiometry is validated with experimental data (Ma et al., 2014a,b). It is shown that the squared correlation coefficients between the calculated and experimental values exceed 90%. Then, the results yielded by the reactor model are compared with another study (Morales and Léonard, 2022) in which more simple kinetics, following a Langmuir-Hinshelwood expression, are implemented. The model developed in this study concludes that a reactor 2.5 times greater is required to reach an equivalent conversion. A discussion is conducted to explore the origin of this divergence, yielding various assumptions. The general expression and catalyst used to regress both models differing, it probably plays a role in this dissimilarity. A specific interest is also given to the kinetics validity range, which varies depending on the assumptions taken to determine it. A fully numerical approach yields a limiting conversion value of 83.5% in base case conditions, while only considering Ma et al. (2014a)’s experimental data leads to a limiting value of 52%. The validity of these approaches is discussed. Eventually, some sensitivity analyses are conducted to observe the reactor model behaviour when some of its parameters and variables are varied. It shows that proper temperature control of the reaction is crucial for reactor performance and that an appropriate tuning of cooling system parameters should be conducted. These sensitivity studies also reveal that an optimal reactor temperature around 210°C and a syngas ratio slightly above 2 maximise the kerosene fraction
selectivity.
The perspectives envisaged for this project are multiple. A particular focus should be given to refining the kinetics validity range and deepening the study of the water kinetic effect, possibly experimentally. Validation of the reactor model with other experimental data seems also relevant. Hopefully, the objective is to conduct those experiments on the future lab-scale installation at ULiège. Si le changement climatique est une évidence, la transition écologique actuelle de notre société est également perceptible. L’utilisation de sources d’énergie renouvelable est d’une importance capitale afin de réduire l’impact environnemental d’origine anthropique. Cependant, leur utilisation présente des désavantages conséquents, notamment leur variabilité. Elles doivent donc pouvoir être stockées à moyen et long terme pour répondre à ce problème, ce qui est possible avec la technologie Power-to-X. Ce travail porte principalement sur la production de e-kérosène à travers la synthèse de Fischer-Tropsch à basse température avec un catalyseur à base de cobalt. Il existe différents modèles de cinétique décrivant cette réaction dans la littérature. L’idée générale derrière ce mémoire est d’identifier le meilleur d’entre eux afin de l’implémenter dans un modèle de réacteur. A terme, celui-ci aidera à comprendre les interactions entre la réaction et le reste du procédé.
Dans ce travail, le modèle cinétique développé par Ma et al. (2014a,b) est spécifiquement étudié.
Par rapport à des cinétiques plus classiques, il inclut un effet cinétique positif induit par l’eau. Un
modèle de réacteur est développé dans Aspen Custom Modeler® dans lequel la cinétique de Ma et al. (2014a,b) est inclue. La stœchiométrie de la réaction est développée selon la théorie d’Anderson-Schulz-Flory en tenant compte de la déviation du méthane par rapport à ce modèle idéal.
L’implémentation de cette cinétique et cette stœchiométrique est validée avec des données expérimentales (Ma et al., 2014a,b). Il est montré que les coefficients de corrélation avec ces données dépassent 90%. Ensuite, les résultats obtenus par le modèle du réacteur sont comparés à une autre étude (Morales and Léonard, 2022), où une cinétique plus simple est mise en œuvre. A conversion équivalente, le volume du réacteur est environ 2,5 plus grand avec le modèle développé dans cette étude. Diverses hypothèses sont posées pour étudier l’origine de cette divergence. L’expression générale et le catalyseur utilisés pour régresser les deux cinétiques étant différents, ils jouent probablement un rôle dans cet écart. Un intérêt particulier est également porté au domaine de validité de cette cinétique. Une approche numérique donne une valeur de conversion limite de 83,5%, que la seule prise en compte des données expérimentales de Ma et al. (2014a) conduit à une valeur limite de 52%. La validité de ces approches est discutée. Enfin, des analyses de sensibilité sont menées pour observer le comportement du modèle lorsque certains de ses paramètres sont modifiés. Elles montrent qu’un contrôle adéquat de la température de réaction est crucial pour les performances et qu’un réglage approprié des paramètres du système de refroidissement doit être effectué. Ces études de sensibilité révèlent également qu’une température optimale autour de 210°C et un rapport de gaz de synthèse légèrement supérieur à 2 maximisent la sélectivité de la fraction kérosène.
Les perspectives envisagées pour ce projet sont multiples. Une attention particulière devrait être
accordée à l’affinement du domaine de validité de la cinétique et à une étude approfondie de l’effet cinétique de l’eau, éventuellement de manière expérimentale. La validation du modèle de réacteur avec d’autres données expérimentales semble également pertinente. L’objectif est de mener ces expériences sur la future installation pilote à l’ULiège.

Fischer-Tropsch --- Power-to-kerosene --- kinetics --- reactor modelling --- Ingénierie, informatique & technologie > Ingénierie chimique

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Between 1999 and 2008, world oil prices more than quadrupled in real terms. For oil importers, vulnerability to oil price increases, defined as the share of gross domestic product spent on net oil imports, rose considerably. Considering medians, low-income countries had the highest vulnerability in 2008 and the highest increase in vulnerability between 1999 and 2008. When changes in vulnerability were decomposed into several contributing factors, more than two-thirds of 170 countries studied were found to have offset the increase in the value of oil consumption by reducing the oil intensity of gross domestic product. Oil intensity fell in more than half the countries in every income group and in every region of the world, driven by falling energy intensity and, to a lesser extent, the oil share of energy. This study also examines the degree of pass-through to consumers of increases in world prices of gasoline, diesel, kerosene, and liquefied petroleum gas between January 2009 and January 2012, when oil prices in nominal U.S. dollars more than doubled. Retail fuel prices varied by two orders of magnitude in 2012, and oil-exporting countries were far less likely to pass on price increases. Gasoline had the highest pass-through, followed by diesel, liquefied petroleum gas, and kerosene. The median pass-through increased with income for gasoline, diesel, and kerosene, but was highest in low-income countries for liquefied petroleum gas. Despite divergent pricing policies, the pass-through coefficients of different fuels were strongly positively correlated, suggesting that the degrees to which domestic prices tracked world prices were comparable for the four fuels in many countries.

Decomposition analysis --- Diesel --- Energy --- Energy and Environment --- Energy intensity --- Energy Production and Transportation --- Environment and Energy Efficiency --- Gasoline --- Kerosene --- Liquefied petroleum gas --- Markets and Market Access --- Oil imports --- Oil intensity --- Oil pricing policy --- Oil Refining & Gas Industry --- Pass-through --- Vulnerability

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Alternative and renewable energy sources already play a very decisive role in the development of human society, helping to fulfill increasing energy demands from both industrialized and underdeveloped countries, as well as economic needs, which must comply with a decarbonized economy, decreasing the energy impact on the global environment. Among these alternative energy sources, fuels such as biodiesel, methanol, and methane are good examples of how the previous design can be achieved, as these fuels can be obtained from renewable sources, used in applications such as transportation systems, electricity generation, fuel conversion, and even for electricity storage, with reduced impact on air emissions. This Special Issue includes papers on new and innovative technical developments or approaches, reviews, case studies, as well as assessment, papers from different disciplines, which are relevant to the optimization of biodiesel, methane/methanol production systems, simultaneously resulting in air quality improvement.

electrolysis --- CaO catalyst --- calcium oxide --- ethanolysis --- synthetic fuels --- eggshell --- photobioreactor --- synthesis gas --- lipid --- hydrotreated kerosene --- renewable energy --- liquefied biomass --- ionic liquid catalyst --- microalgae --- methanolysis --- ß-carotene --- power plant exhaust gas --- biodiesel --- biomass --- heterogeneous catalysis --- economic analysis --- seafood inorganic wastes --- sustainability --- FAME --- microalgae culture --- solid base heterogeneous catalyst --- transesterification --- micro- and nano-structured catalysts --- vegetable oils --- acid mine drainage --- HY zeolite --- animal fats --- nano-catalyst

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Unable to cope fully with steadily climbing world oil prices since mid-2009, many of the 65 countries reviewed in this paper have progressed slowly or even reversed course in reforming pricing of petroleum products. End-user prices in July 2012 varied by two orders of magnitude across the countries. More than two-fifths, including some that had only recently adopted automatic pricing mechanisms, froze the prices of gasoline, diesel, or both for months or even years on end during the study period. When the prices were finally adjusted, the increases were sometimes substantial, leading to large-scale protests, partial or full reversals of price adjustments, or softening of pricing reform policy. Governments' attempts to keep domestic prices artificially low-through price control, export or quantity restrictions, or political pressure put on oil companies-have helped curb inflation in the short term, but frequently with serious negative consequences: flourishing black markets, smuggling, fuel adulteration, illegal diversion of subsidy funds, large financial losses suffered by fuel suppliers, deteriorating refining and other infrastructure, and acute fuel shortages causing economy-wide damage. In several countries, subsidies, price controls, and other restrictions have helped protect inefficient refineries and oil marketers. Mitigation responses have included fuel conservation programs; fuel diversification, particularly liquid biofuels to substitute gasoline and diesel; and efforts to lower costs of supply, including strengthening infrastructure, promoting price competition, hedging, negotiating price discounts with exporters, and bulk procurement. Various forms of assistance to consumers have also been offered, especially to households, agriculture, transport, and fisheries.

Access to Markets --- Biodiesel --- Biofuel --- Conservation --- Diesel --- Diversification --- Energy --- Energy efficiency --- Energy Production and Transportation --- Ethanol --- Gasoline --- Kerosene --- Liquefied petroleum gas --- Markets and Market Access --- Oil pricing policy --- Oil Refining & Gas Industry --- Renewable energy --- Social protection --- Subsidies --- Transport Economics Policy & Planning