Dissertations / Theses: 'Alkanol'

1

Lam, Daniel H. "Multiphase equilibrium behavior of ethane, nitrous oxide and carbon dioxide + n-alkanol binary and ternary mixtures /." Access abstract and link to full text, 1990. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9034205.

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2

Amadio, Emanuele <1981&gt. "Oxidative carbonylation of alkanols catalyzed by Pd(II)-phosphine complexes." Doctoral thesis, Università Ca' Foscari Venezia, 2010. http://hdl.handle.net/10579/946.

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The complexes trans–[Pd(COOR)(H2O)(PPh3)2](TsO) (R = Me, Et, nPr, iPr, nBu, iBu, secBu) and trans–[Pd(COOR)nX2–n(PPh3)] (R = Me, n = 1, 2; X = ONO2, ONO, OTs, Br. R = iPr, n = 1, X = Cl, Br) have been synthesised and characterised. Most of them have been used as catalyst precursors for the oxidative carbonylation of MeOH, selective to dimethyloxalate, using p–benzoquinone (BQ) as an oxidant. BQ changes properties of the reaction centre. When using iPrOH in place of MeOH, high activity and selectivity toward diisopropyloxalate have been achieved using trans–[PdX2(PAr3)2] with strongly coordinating X (Br), in presence of a base (NEt3 or PAr3–BQ adduct) and of an excess of LiBr. The slow step of the catalysis (RDS) might be the reoxidation of Pd(0), which is formed in the product–forming step. Using [PdX2(P-P)] the best performance has been achieved with weakly coordinating X (TsO) and using P-P of relatively wide bite angle but with cis–geometry. The RDS is related to the nature of P-P.
Sono stati sintetizzati e caratterizzati i complessi trans–[Pd(COOR)(H2O)(PPh3)2](TsO) (R = Me, Et, nPr, iPr, nBu, iBu, secBu) e trans–[Pd(COOR)nX2–n(PPh3)] (R = Me, n = 1, 2; X = ONO2, ONO, OTs, Br. R = iPr, n = 1, X = Cl, Br). Molti sono stati utilizzati come precursori catalitici nella carbonilazione ossidativa di MeOH, selettiva a dimetiloxalato, impiegando p–benzochinone (BQ) come ossidante. Il BQ modifica le proprietà del centro di reazione. Con iPrOH al posto di MeOH si ottengono elevate attività e selettività a diisopropyloxalato utilizzando trans–[PdX2(PAr3)2] con X fortemente coordinanti (Br), in presenza di base (NEt3 o PAr3–BQ) e di LiBr in eccesso. Lo stadio lento della catalisi (RDS) potrebbe essere la riossidazione del Pd(0) che si forma nello stadio di formazione dell’ossalato. Con [PdX2(P-P)] le migliori prestazioni sono state ottenute con X debolmente coordinanti (TsO) e con P-P ad angolo di morso relativamente ampio ma di geometria cis. L’ RDS dipende da P-P.

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3

Wang, Zhong. "Synthesis of bioactive fluorinated bile acid analogues and investigating the influence of (deoxo)fluorination on alkanol and carbohydrate lipophilicity by a new logP determination method." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/397966/.

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Since the identification of bile acids as natural ligands for FXR and TGR5 receptors, huge interest has arisen in this field, including the synthesis of semi-synthetic bile acid derivatives to increase binding potency and selectivity. Fluorine introduction is an attractive strategy in drug design and property optimization. This thesis describes the synthesis of fluorinated analogues of bile acids and the lead compound 6-ECDCA. Interesting observations of effects of fluorination on crystal packing modes will also be discussed. Another important application of fluorination is lipophilicity (logP) modulation. However, logP measurement of non-UV active compounds is rather cumbersome and hampers research toward the understanding how aliphatic fluorination influences lipophilicity. Over the course of this thesis, a novel and straightforward method was developed for accurate measurement of lipophilicity of fluorinated compounds by using 19F NMR. Unlike many other methods, there is no requirement of UV activity for quantification, or the need for calibration curves for logP estimation. Using this method, logP values for a large number of fluorinated compounds were determined. Interesting effects and trends from different fluorination patterns were observed, along with the impact of stereochemistry on lipophilicity.

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4

Wassermann, Tobias N. "Umgebungseinflüsse auf die C-C- und C-O-Torsionsdynamik in Molekülen und Molekülaggregaten Schwingungsspektroskopie bei tiefen Temperaturen." Berlin Logos, 2009. http://d-nb.info/1000809706/04.

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5

Khalil, Enam A. S. A. "A thermodynamic study of binary and ternary mixtures of some alkanes and alkanols." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328889.

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6

Favre, Éric. "Modélisation de l'équilibre de sorption et du transfert de matière dans des membranes à base de polydiméthylsiloxane : application à l'extraction d'alcanols de solutions aqueuses par pervaporation." Vandoeuvre-les-Nancy, INPL, 1994. http://docnum.univ-lorraine.fr/public/INPL_T_1994_FAVRE_E.pdf.

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Le but de ce travail est d'étudier l'extraction de composés organiques de solutions aqueuses par pervaporation sous l'angle du transfert de matière dans la membrane; l'équilibre de sorption et la diffusion de l'eau et d'une série d'alcanols (éthanol à pentanols) dans le polydimethylsiloxane (PDMS) ont été étudiés. La théorie de Flory-Huggins classique ne permet pas de décrire correctement les isothermes de sorption obtenus; une analyse des données d'équilibre, basée sur un critère thermodynamique (Zimm & Lundberg), montre que les molécules d'alcanols ont une tendance à l'autoassociation dans le PDMS (formation de clusters). Les résultats sont correctement décrits par une nouvelle approche mécanistique, postulant l'existence d'affinités élémentaires entre les molécules de solvant et la matrice polymère d'une part, les molécules congénères d'autre part; le modèle conduit à une équation d'équilibre contenant deux paramètres ajustables qui permet la description correcte de nombreux systèmes binaires dans les polymères. La diffusion d'un perméant unique dans le PDMS a été étudiée par la technique de perméation de vapeur; la tendance à la décroissance des coefficients de diffusion avec la fraction volumique en pénétrant correspond qualitativement à l'ordre de tendance à la formation de clusters, dégagé de l'étude de sorption. Dans le dernier chapitre, l'influence de la concentration en alcool et de la température de la charge sur les flux partiels de pervaporation est présentée

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ZHENG, TAO. "MOLECULAR SIMULATION OF DIFFUSION AND SORPTION OF ALKANES AND ALKANE MIXTURES IN POLY[1-(TRIMETHYLSILYL)-1-PROPYNE]." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin973701057.

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8

Correia, Leslie Daniel Camara. "Oxygen transfer in hydrocarbon-aqueous dispersions and its applicability to alkane-based bioprocesses." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/999.

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Criswell, Leah. "Neutron diffraction and quasielastic neutron scattering studies of films of N-alkanes and a branched alkane absorbed on graphite." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/6010.

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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 11, 2008) Includes bibliographical references.

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10

Cheema, Shabaz Ahmad. "The atmospheric oxidation of alkanols." Thesis, University of Hull, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310212.

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11

García, Ojeda José Luis [Verfasser], and Rudolf [Akademischer Betreuer] Müller. "Oxidation of long-chain n-alkanes by mutants of a thermophilic alkane-degrading bacterium: Thermus sp. ATN1 / José Luis García Ojeda. Betreuer: Rudolf Müller." Hamburg-Harburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2014. http://d-nb.info/1048647358/34.

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12

Bishop, Margaret. "IR laser photochemistry of alkanols and 3,3-dimethyloxetane." Thesis, University of Hull, 1991. http://hydra.hull.ac.uk/resources/hull:6980.

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In this work, a pulsed CO₂ laser was used to excite methanol, ethanol, propan-2-ol, butan-2-ol, t-butanol, pentan-2-ol, hexan-2-ol, and 3,3-dimethyloxetane in order to study how these moleCUles absorb laser energy and decompose. The dependence of absorbed energy and fractional yield on laser parameters such as irradiating wavelength.,fluence and pulse type, and on reactant molecular size, pressure and diluent, was examined. The absorbed energy was measured using the optoacoustic (OA) technique. A new method for calibrating the OA cell was developed and is described in full in the thesis. The approach enables calibration to be extended to lower absorption levels (about 200µJ for a signal-to-noise ratio of six) than is possible with the more usual transmission methods, and was found to be capable of measuring as little as 5µJ. A particular advantage of the technique, is that it is simple, rapid, and provides an immediate visual indication of the absorption level. It is observed, for all reactants studied, that the absorption cross-section at low pressure was less than at high pressure, but that the difference diminishes with molecular size with the absorption cross-section taking on a value comparable to that of the small signal, broadband cross-section. These findings are consistent with the explanation that rotational hole-burning exists, but decreases in importance as the molecular size, and hence density of states, increases. As the fluence is varied, the absorption cross-section is found to increase with decreasing fluence towards the small signal, broadband value. With increasing molecular size the increase is less noticeable, and the absorption cross-section takes on the value comparable to that of the small signal, broadband cross-section. With increasing alkanol molecular size, it is observed that the major decomposition products can always be explained in terms of a molecular elimination channel i.e. one of dehydration. Also, the number of minor products and their yields both increase. It is believed that most of the minor products arise as a consequence of carbon-carbon fission processes, with minor contributions due to molecular elimination.

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13

Peter, Sebastian. "Oxyfunctionalization of alkanes, alkenes and alkynes by unspecific peroxygenase (EC 1.11.2.1)." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-113321.

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Unspecific peroxygenase (EC 1.11.2.1) represents a group of secreted hemethiolate proteins that are capable of catalyzing the selective mono-oxygenation of diverse organic compounds using only H2O2 as a cosubstrate. In this study, the peroxygenase from Agrocybe aegerita (AaeUPO) was found to catalyze the hydroxylation of various linear (e.g n-hexane), branched (e.g. 2,3-dimethylbutane) and cyclic alkanes (e.g. cyclohexane). The size of n-alkane substrates converted by AaeUPO ranged from gaseous propane (C3) to n-hexadecane (C16). They were mono-hydroxylated mainly at the C2 and C3 position, rather than at the terminal carbon, and the corresponding ketones were formed as a result of overoxidation. In addition, a number of alkenes were epoxidized by AaeUPO, including linear terminal (e.g. 1-heptene), branched (2-methyl-2-butene) and cyclic alkenes (e.g. cyclopentene), as well as linear and cyclic dienes (buta-1,3-diene, cyclohexa-1,4-diene). Furthermore, the conversion of terminal alkynes (e.g. 1- octyne) gave the corresponding 1-alkyn-3-ol in low yield. Some of the reactions proceeded with complete regioselectivity and - in the case of linear alkanes, terminal linear alkenes and alkynes - with moderate to high stereoselectivity. The conversion of n-octane gave (R)-3-octanol with 99% enantiomeric excess (ee) and the preponderance of the (S)-enantiomer reached up to 72% ee of the epoxide product for the conversion of 1-heptene. Catalytic efficiencies (kcat/ Km) determined for the hydroxylation and respectively epoxidation of the model compounds cyclohexane and 2-methyl-2-butene were 2.0 × 103 M-1 s-1 and 2.5 × 105 M−1 s−1. The results obtained in the deuterium isotope effect experiment with semideuterated n-hexane and the radical clock experiment with norcarane clearly demonstrated that the hydroxylation of alkanes proceeds via hydrogen abstraction, the formation of a substrate radical and a subsequent oxygen rebound mechanism. Moreover, stopped-flow experiments and substrate kinetics proved the involvement of a porphyrin radical cation species (compound I; AaeUPO-I) as reactive intermediate in the catalytic cycle of AaeUPO, similar to other hemethiolate enzymes (e.g. cytochrome P450 monooxygenases, P450s)
Die Gruppe der Unspezifischen Peroxygenasen (EC 1.11.2.1) umfasst extrazelluläre Häm-Thiolat-Enzyme, die mittels H2O2 als Cosubstrat die selektive Monooxygenierung unterschiedlicher organischer Verbindungen katalysieren. In der vorliegenden Arbeit konnte gezeigt werden, dass die von Agrocybe aegerita sekretierte Peroxygenase (AaeUPO) verschiedene lineare (z. B. n-Hexan), verzweigte (z. B. 2,3-Dimethylbutan) und zyklische Alkane (z. B. Cyclohexan) hydroxyliert. Die Größe der von der AaeUPO umgesetzten Substrate reichte vom gasförmigen Propan (C3) bis hin zu n-Hexadekan (C16). Die Alkane wurden bevorzugt am zweiten und dritten Kohlenstoffatom (C2 und C3) hydroxyliert; eine Hydroxylierung am terminalen Kohlenstoff konnte nur vereinzelt und in geringem Umfang beobachtet werden. Die Überoxidationen der primär gebildeten, sekundären Alkohole führte außerdem zur Entstehung der entsprechenden Ketonderivate. Darüber hinaus wurde eine Vielzahl linearer terminaler (z. B. 1-Hepten), verzweigter (z. B. 2-Methyl-2-Buten) und zyklischer Alkene (z. B. Cyclopenten) sowie linearer und zyklischer Diene (1,3-Butadien, 1,4-Cyclohexadien) durch die AaeUPO epoxidiert. Die Umsetzung terminaler Alkine (z. B. 1-Octin) führte zur Entstehung der jeweiligen 1-Alkin-3-ole. Manche dieser Reaktionen verliefen ausgeprägt regioselektiv und, im Falle der linearen Alkane sowie der linearen terminalen Alkene und Alkine, mit mittlerer bis hoher Stereoselektivität. So ergab beispielsweise die Umsetzung von n-Octan einen Enantiomerenüberschuss größer 99% für (R)-3-Octanol; die Epoxidierung von 1-Hepten lieferte einen Enatiomeerenüberschuss (ee) von bis zu 72% für das (S)-Enantiomer. Die katalytischen Effizienzen, die für die Hydroxylierung bzw. Epoxidierung der Modellverbindungen Cyclohexan und 2-Methyl-2-Buten ermittelt wurden, betragen 2.0 × 103 M-1 s-1 und 2.5 × 105 M−1 s−1. Der ausgeprägte Deuterium-Isotopen-Effekt, der im Zuge der Umsetzung von semideuteriertem n-Hexan beobachtet wurde sowie die Ergebnisse des Radical-Clock-Experiments mit Norcarane als Substrat bestätigten, dass die Hydroxylierung von Alkanen über Wasserstoffabstraktion, die Bildung eines Substratradikals und anschließende direkte Sauerstoffrückbindung verläuft. Die Stopped-Flow-Experimente belegen zudem das Auftreten eines Porphyrin-Kationradikal-Intermediates (Compound I; AaeUPO-I) im katalytischen Zyklus der AaeUPO (vergleichbar mit dem reaktiven Intermediat der P450-Monooxygenasen)

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14

Løften, Thomas. "Catalytic isomerization of light alkanes." Doctoral thesis, Norwegian University of Science and Technology, Department of Chemical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1909.

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In recent years the levels of sulfur and benzene in the gasoline pool have been reduced, and in the future there may also be new regulations on vapor pressure and the level of aromatics and olefins as well. The limitations on vapor pressure and aromatics will lead to reduced use of C₄ and reformate respectively. The branched isomers of C₅ and C₆ alkanes have high octane numbers compared to the straight chain isomers, and are consequently valuable additives to the gasoline pool. To maintain the octane rating, it is predicted that an increased share of isomerate will be added to the gasoline pool.

Today there is a well established isomerization technology with platinum on chlorided alumina as the commercial catalyst for both isomerization of n-butane and of the C₅/C₆ fraction. This catalyst is very sensitive to catalyst poisons like water and sulfur, and strict feed pretreatment is required. Zeolites promoted by platinum are alternatives as isomerization catalysts, and has replaced Pt/alumina catalysts to some extent. The Pt/zeolite catalyst is more resistant to water and sulfur compounds in the feed, but it is less active than platinum on chlorided alumina. It does therefore require a higher reaction temperature, which is unfortunate since the formation of the branched isomers of the alkanes is thermodynamically favored by a low temperature.

Because of the limitations of the two types of isomerization catalysts, there is a search for a new catalyst that is resistant to sulfur and water in the feed and is highly active so it can be operated at low temperature. A new type of catalyst that seems to be promising in that respect is sulfated zirconia.

The first part of this study focuses on a series of iron and manganese promoted SZ catalysts. The catalysts were characterized by various techniques such as XRD, TGA, N₂adsorption and IR spectroscopy of adsorbed pyridine. The catalytic activity in n-butane isomerization at 250°C and atmospheric pressure was compared to the physical and chemical properties of the samples. No promoting effect of iron and manganese was found when n-butane was diluted in nitrogen. When nitrogen was replaced by hydrogen as the diluting gas the activity of the unpromoted SZ sample was dramatically lowered, while the activity of the promoted catalyst was not significantly changed.

If we only consider the promoted samples, the catalytic activity increases with increasing iron/manganese ratio. We also observe that the activity of the samples is clearly correlated with the number of strong Brønsted acid sites. The total number of strong acid sites (i.e. the sum of Brønsted and Lewis sites) does not change significantly when the promoter content is changing, hence no correlation between catalytic activity and the total number of acid sites is found. This underlines the importance of discrimination between Lewis and Brønsted acidity when characterizing the acidity of the samples.

The second part of this study is focused on a series of noble metal promoted sulfated zirconia. Their catalytic activity in n-hexane isomerization at high pressures was compared to a commercial Pt/zeolite catalyst. Among the noble metal promoted samples the catalyst promoted with platinum was the most active. The samples promoted with rhodium, ruthenium and iridium showed equal activity.

Common for all the noble metal promoted catalysts is the large increase in activity when catalysts are reduced with hydrogen compared to when they are pretreated in helium. The increase in activity is most likely connected to the reduction of the metal oxides of the promoters to ensure that the promoters are in the metallic state. Reduction at too high temperatures does however give lower activity. This is probably due to the reduction of surface sulfate groups leading to a loss in acid sites.

The commercial sample was considerably less active than the sample of platinum promoted sulfated zirconia. The commercial catalyst was however more stable than the PtSZ catalyst. All the sulfated zirconia catalysts deactivated, but the initial activity could be regenerated by reoxidation at 450°C followed by reduction at 300°C. The promotion with noble metals appears to inhibit coke formation on the catalyst. But, the main cause of deactivation of the platinum promoted sample is most likely the reduction of sulfate species leading to a loss of acid sites.

The kinetic study of the catalysts indicates that the n-hexane isomerization proceeds via a classical bifunctional mechanism where the role of the promoting metal is to produce alkenes, which are subsequently protonated on the acid sites. The reaction orders of hydrogen, n-hexane and total pressure are all in accordance with this mechanism. The activation energies of the catalysts are within the typical range of bifunctional catalysts.

All catalysts, except the unpromoted SZ sample, showed close to 100% selectivity to branched hexane isomers and a similar distribution of these isomers. The isomer distribution being the same for both the noble metal promoted catalyst and the Pt/zeolite is another indication that the isomerization proceeds via the bifunctional mechanism over the promoted samples. The different selectivity of the unpromoted SZ catalyst indicates that the isomerization proceeds via a different pathway over this catalyst; this is probably a pure acidic mechanism

The acidity characterization can not explain the differences in isomerization activity. It is however likely that the activity of the promoting metals in the dehydrogenation of alkanes is important since the classical bifunctional mechanism is prevailing.

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15

Pongtavornpinyo, Ruti. "Indium Carbenes Alkenes and Alkanes." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508494.

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16

Marozzelli, Filippo. "Alkanes activation over oxide catalysts." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/60089/.

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The basics of the oxidation mechanism of different alkanes within zeolites and over molybdenum oxide surfaces were studied employing state of the art computational modelling. It was shown that the constrained environment inside MFI, MFS and MOR induces terminal selectivity on the reaction of 6-, 8- and 10- term linear alkanes, i.e. hexane, octane and decane, respectively. The Monte Carlo (MC) random alkane configuration sampling showed that the oxidation reactivity is driven by the fact that the terminal C atoms of the substrate are more likely to be closer to the zeolites internal walls than the methylene (–CH2–) C atoms. As a confirmation of this, the calculation of kprim/ksec for all the host/guest (alkane/zeolite) systems estimated that the pore effect exerted by the zeolites in the reaction favors terminal products (terminal selectivity). The alkane oxidation over MoO3(010), Fe2(MoO4)3(001) and (110) surfaces involved the activation of a C–H bond of the substrate. The surface calculations were carried out using DFT+U to localize the electrons at a terminal point of the surface. Energy comparison with hybrid DFT (B3LYP) calculations for cluster models of the MoO3(010) surface showed consistency with the DFT+U results. The propane terminal C–H bond activation generated a propyl radical. Transition state structures were found for the adsorption of radical species on MoO3(010) and Fe2(MoO4)3(001) surface and the corresponding energy barriers showed that the adsorption on the former system is favored, which indicates that the Fe2(MoO4)3 surface alone is not a good catalyst for the reaction studied.

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Imbert, F. E. "Aspects of alkane decomposition." Thesis, Swansea University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637369.

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Weiguo, Shen. "Thermodynamics of alkane solutions." Thesis, University of Canterbury. Chemical and Process Engineering, 1988. http://hdl.handle.net/10092/7727.

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An apparatus for static vapour pressure measurements on pure liquids and on binary and ternary mixtures containing one involatile component has been designed and constructed. The apparatus and corresponding experimental techniques have been tested and experimental errors have been discussed. Measurements have been made of the vapour pressures of binary mixtures of n-hexane + n-hexadecane at 298.15 K and 303.15 K and of binary mixtures of n-hexane + n-octane, n-octane + n-hexadecane, and ternary mixtures of n-hexane + n-octane + n-hexadecane at 298.15 K. The experimental measurements of pressures (P) vs mole fractions (x) have been fitted to the Redlich-Kister equation by Barker's method to obtain activity coefficients of each component in the liquid phase, the excess Gibbs functions, and the mole fractions in the vapour phase. The results for n-hexane + n-hexadecane at 303.15 K have been compared with those of previous work (Williamson, 1957) and the agreement is reasonably good. The excess volumes of n-hexane +benzene, n-dodecane + 2-methylpentane and pseudo n-dodecane prepared from equimolar numbers of n-decane + n-tetradecane + each of four branched hexane isomers at 298.15 K have been obtained from measurements of the densities of pure compounds and mixtures with a vibrating tube densimeter. Two methods for preparation of mixtures of which densities are required to be accurately measured have been designed and compared with each other. The excess enthalpies of 2-methylpentane with n-dodecane and with each of three pseudo n-dodecanes prepared from equimolar mixtures of n-decane + n-tetradecane, n-undecane + n-tridecane, and n-octane + n-hexadecane, and the excess enthalpies of equimolar decane + tetradecane mixture with each of the other three branched hexane isomers at 298.15 K have been measured with an isothermal displacement calorimeter. The experimental results of binary mixtures have been discussed in term of the principle of congruence with Hijmans' graphical method and Bellemans and Mat's analytical formula. New graphical tests of the principle of congruence and a modified Bellemans and Mat equation for ternary mixtures have been developed and applied to the experimental p-x data of ternary systems. The agreement between the experimental values and those predicted by the principle are excellent. The modified Bellemans and Mat equation seems to be more powerful than and preferable to the Redlich-Kister equation for the systems investigated in this work.

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Xu, Xiangrong. "Uranyl ion sensitised photooxidation of alkanes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq27436.pdf.

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Gomes, Ana Catarina Costa. "Photocatalysis : Carbonylation of arenas and alkanes." Thesis, University of York, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516370.

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Smith, Paul Andrew. "Simulation studies of alkanes and surfactants." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314225.

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Shiimi, Annatolia. "Modeling Diiron enzymes for alkanes activation." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/10669.

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Includes abstract.
Includes bibliographical references.
The synthesis and characterization of a series of ruthenium 'sawhorse' complexes of the type [RU2(IJ-02CRh(CO)4(Lh]' has been successfully carried out. The complexes have been characterized by IR, 1H and 13C NMR spectroscopy, elemental analysis as well as by mass spectrometry.

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Perry, Jason Kendrick Goddard William A. "Alkane activation by first, second, and third row transition metal ions organometallic chemistry in the gas plate /." Diss., Pasadena, Calif. : California Institute of Technology, 1994. http://resolver.caltech.edu/CaltechTHESIS:11122009-152204878.

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Thesis (Ph. D.)--California Institute of Technology, 1994. UM #94-27,313.
Advisor names found in the Acknowledgements pages of the thesis. Title from home page. Viewed 01/14/2010. Includes bibliographical references.

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Hooper, Andrew David. "Alkane hydrogenolysis on ruthenium catalysts." Thesis, Brunel University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302574.

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25

Newell, Helen E. "Alkane adsorption on metal surfaces." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243748.

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26

Huang, Zheng Brookhart Maurice S. "Alkane metathesis via tandem catalysis." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2009. http://dc.lib.unc.edu/u?/etd,2576.

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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2009.
Title from electronic title page (viewed Oct. 5, 2009). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.

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Ramakrishnan, Ayyappan. "Visible light induced catalytic sulfoxidation of alkanes." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981136915.

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28

Putra, Edy Giri Rachman. "Solution crystallization of long chain n-alkanes." Thesis, University of Sheffield, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401188.

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29

Gallagher, P. "The reductive decomposition of bis-diazo-alkanes." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381343.

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30

Su, Yee San 1977. "The heterogeneous partial oxidation of light alkanes." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28306.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2004.
Includes bibliographical references.
(cont.) With this approach, an upper bound on the yield for OCM was computed. Results showed that even with optimal surface chemistry, strict limits existed on the attainable yield. Surface energetics necessary for superior OCM performance were identified and the origins of these requirements elucidated. The resulting upper bound on OCM yield under conventional, packed-bed, continuous-feed operation was found to be 28%. The catalytic properties of LiCl/sulfated ZrO₂-based catalysts were explored for ODHE. LiCl was shown to strongly interact with the acid sites on sulfated ZrO₂ (SZ), influencing its catalytic behavior. Two approaches were taken to modify the nature/strength of the LiCl-support interaction. Firstly, LiCl/Nd₂O₃-impregnated MoO/ZrO₂ and WOx/ZrO₂ were examined. Unlike SZ, these supports allowed for the tailoring of MoO[sub]x and WO[sub]x surface densities, which in turn drastically altered their ODHE performance. The poor stability of these supports, however, rendered them inferior to SZ. Secondly, the effects of dopant incorporation on the catalytic behavior of LiCI/MO,/SZ were studied. Si-doped ZrO₂-based catalysts synthesized via the sol-gel method were found to exhibit superior activity, selectivity and stability for ODHE. Sulfate decomposition experiments related the ODHE activity of these materials to the influence of the Si dopant on the sulfate binding strength. The sol-gel synthesis conditions were optimized with respect to sol pH, water:alkoxide ratio and silicon precursor, achieving improved catalyst homogeneity and enhanced ODHE performance ...
Within the petrochemical industry, a sizeable economic incentive exists for the upgrading of low-value, light alkanes. For instance, the dehydrogenation of ethane to ethene is of considerable interest due to ethene's use as a polymeric and chemical precursor. Partial oxidation provides an attractive alternative to standard pyrolysis methods for alkane-to-alkene conversion. Unlike pyrolysis, partial oxidative routes are largely unaffected by coke formation and have the added benefit of exothermicity. With the inclusion of oxygen as a reactant, however, numerous additional reaction pathways result. Among these, the presence of parallel and consecutive reaction channels to CO[sub]x products is of major concern. For this reason, previous efforts to create selective partial oxidation catalysts with high activity have typically fallen below economic feasibility requirements. This thesis focuses on the following alkane-to-alkene transformation reactions: Oxidative Coupling of Methane (OCM): 2CH₄ + O₂ <--> C₂H₄ + 2 H₂O Oxidative Dehydrogenation of Ethane (ODHE): C₂H₆ + 1/2 O₂ <--> C₂H₄ + H₂O Oxidative Dehydrogenation of Propane (ODHP): C₃H₈ + 1/2 O₂ <--> C₃H₆ + H₂O. Regarding OCM, an approach was presented for determining an upper bound on the yield of a catalytic process, which allowed for variations in the catalytic chemistry. Scaling and thermodynamic arguments were used to set parameters of an elementary step surface mechanism at values resulting in optimal yields, subjected only to physical constraints. Remaining unknowns were treated as independent variables and varied over a broad range. The result was a set of thermodynamically consistent mechanisms with optimal kinetics that could be incorporated into reactor-transport models.
by Yee San Su.
Ph.D.

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31

Grant, C. R. "Evaluation of the bio-oxidation of alkanes." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1367613/.

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This thesis documents the progress made in utilising the alkane hydroxylase complex of P.putida GPo1 expressed in E.coli as a whole-cell biocatalyst for the oxidation of n-dodecane to 1-dodecanol. The process is of considerable interest due to the difficulty in performing the reaction using conventional chemistry and the large global market for fatty alcohols. The first results chapter compares the fermentative bio-oxidations using E.coli pGEc47ΔJ on n-octane and n-dodecane in a stirred tank reactor. The first reported conversion of n-dodecane in-vivo using this enzyme system in a recombinant host is reported. A number of bottlenecks were identified in this chapter; in particular, (i) poor induction of the alkS expression system with ndodecane, which controls the expression of the alk enzymes (ii) a suspected mass transport limitation (iii) substantial over-oxidation of the desired 1- dodecanol product to dodecanoic acid. The second results chapter firstly describes the development of a microwell platform in order to characterise the system more efficiently. Phase mixing limitations and organic phase spillage/evaporation were overcome in order to develop the microwell platform for the fermentative bio-oxidation which is the first reported microwell scale-down which matches the volumetric and specific rates achieved in a bioreactor for a substrate of such low solubility. Secondly, the microwell platform was used with design of experiments (DoE) methodology to rapidly and systematically characterise the overoxidation issue and identify appropriate solutions. Using this approach, substrate solubility was identified as the most critical factor affecting the tendency for overoxidation; the use of cosolvents to improve n-dodecane solubility in the aqueous phase was found to improve the 1-dodecanol yields and reduce dodecanoic acid yields. Oxygen availability and carbon source availability also proved important factors in the extent of overoxidation. Despite the improvements made the problem was only partially overcome and it was decided, based on the results, that biological engineering of the strain was necessary to remove the downstream aldehyde dehydrogenase alkH which was likely to be exacerbating overoxidation. The process of designing and constructing 3 new plasmids is described in results chapters four and five. These plasmids were designed with the aim of identifying the role of various alk proteins and ultimately identifying ways of improving substrate access to the enzyme and reducing overoxidation. It was found as a result of this work that overoxidation was reduced by removal of alkH but that the alkane-1-monooxygenase alkB was still capable of direct overoxidation to the dodecanoic acid even in the absence of alkH. More significantly, the function of an outer membrane protein of unknown function was also confirmed by this work. It was found to be essential for conversion of n-dodecane in-vivo but was also found to be toxic to the host organism when overexpressed. Finally, it was found that the alkane-1-monooxygenase enzyme system was also capable of C14 and C16 alkane oxidation; this has not previously been reported in literature in-vivo.

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Waldstein, Nathaniel A. "Analysis of pump oil and alkanes evaporation." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002786.

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Winpenny, John Philip. "The effects of some simple, model anaesthetic compounds on a transient potassium current (Iâ†A) in identified Helix aspersa neurones." Thesis, University of Dundee, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282741.

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Grootboom, Natasha Denise. "Alkane oxidation using metallophthalocyanine as homogeneous catalysts." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1007794.

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Iron polychlorophthalocyanine (FePc(Cl)₁₆) and tetrasulfophthalocyanine ([M¹¹TSPc]⁴) complexes of iron, cobalt and manganese are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), chloroperoxybenzoic acid (CPBA) and hydrogen peroxide as oxidants. Catalysis using the FePc(Cl)₁₆ was performed in a dimethylformamide:dichloromethane (3 :7) solvent mixture. For the [Fe¹¹TSPc]⁴⁻, [Co¹¹TSPc]⁻ and [Mn¹¹TSPc]⁴⁻catalysts, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative percentage yields, percentage selectivity and overall percentage conversion of the products depended on types of oxidant, or catalyst, concentrations of substrate or catalysts and temperature. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. Of the four catalysts investigated [Fe¹¹TSPc]⁴⁻ yielded the highest overall percentage conversion of 20%.The mechanism of the oxidation of cyclohexane in the presence of the FePc(Cl)₁₆ and [M¹¹TSPc]⁴⁻ involves the oxidation of these catalysts, forming an Fe(IlI) phthalocyanine species as an intermediate. Electrocatalysis using [Co¹¹TSPc]⁴⁻ as catalyst, employed an aqueous pH 7 buffer medium for electro-oxidation of 4-pentenoic acid. An enone is suggested as the only oxidation product of 4-pentenoic acid. No degradation of [Co¹¹TSPc]⁴⁻ was observed during the electrocatalytic process. In this process water was used as a source of oxygen therefore eliminating the production of by products from oxidant as in the case of TBHP and CPBA. This system was studied In an attempt to set up conditions for alkane electrocatalytic oxidation.

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35

Bouyer, Maouen Abdelkarim. "Computer simulations of alkane-zeolite systems." Doctoral thesis, Universite Libre de Bruxelles, 1998. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212049.

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36

Jones, Ian W. "COMPUTATIONAL STUDIES OF DISUBSTITUTED BICYCLO[m.m.m]ALKANE AND DISUBSTITUTED BICYCLO[8.8.n]ALKANES, SYNTHESIS OF 1,10-DIMETHYLBICYCLO[8.8.8]HEXACOSANE AND 1,10-DIHYDROXYBICYCLO[8.8.8]HEXACOSANE, AND PROGRESS TOWARDS THE SYNTHESIS OF A DISUBSTITUTED 1,10-." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193585.

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Polymers possess bulk elastic properties due to entanglement of the polymer chains, not due to an inherit elasticity found within the monomers. An appropriately disubstituted bicyclo[8.8.8]hexacosane monomer should impart inherit elasticity when utilized in a polymer. A stochastic search of disubstituted bicyclo[m.m.m]alkanes demonstrated that these systems will adopt an out,out configuration and bicycles with medium and large values of m possess variable bridgehead-bridgehead distances. A stochastic search of disubstituted bicyclo[8.8.n]alkanes demonstrated an even-odd effect within the bite-angle of the bicycle. Two model compounds with methyl and hydroxyl groups at the bridgehead carbons were synthesized that demonstrated solid-state structures that correlated extremely well with the computational search. The solid-state structures were observed with both an out,out configuration and variable bridgehead-bridgehead distances. To investigate this hypothesis, polyurethanes will be made from the following diol monomers: 1,10-decanediol, a monocyclic diol, and a bicyclo[8.8.8]hexacosane diol.

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37

Kleinschmidt, Olaf. "Photokatalytische Oxidation von Alkenen und Alkanen mit Sauerstoff an belichtetem Titandioxid." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=962781142.

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Weidinger, Inez Marita. "Untersuchungen zum Gefrierverhalten levitierter n-Alkan- Mikrotropfen." [S.l. : s.n.], 2003. http://www.diss.fu-berlin.de/2003/152/index.html.

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39

Stevenson, Julie-Anne. "Selective oxidation of simple alkanes by cytochrome P450cam." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302491.

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40

El, Nikheli A. H. D. "Phase equilibria in mixtures containing alkanes and alcohols." Thesis, Loughborough University, 1987. https://dspace.lboro.ac.uk/2134/10419.

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Vapor-liquid equilibria (VLE) in alkanes and alcohols was measured and a contribution Patel-Teja (GPT) equation proposed in this work. systems of nmodified Group of state was Isothermal vapor-liquid equilibria at temperatures between 298.7K and 333. 7K have been measured for the binary systems n-pentane + n-hexane. n-pentane + noctane. n-pentane + n-decane. and n-pentane + l-propanol. The data were found to be consistent according to a point-to-point consistency test and were correlated using the Wilson. NRTL. and UNIQUAC activity coefficient models. The parameters of the models were estimated using the maximum likelihood principle. A new version of the Group contribution Patel-Teja equation of state was proposed in which a new temperature dependent group interaction expression was introduced. Group interaction parameters for four constituent groups of the alcohols and n-alkanes (viz. CH 2• CH 3 • CH and OH) were determined. These parameters were then used for the prediction of VLE in mixtures of n-alkane + n-alkane. n-alkane + n-alcohol. and n-alcohol + n-alcohol. VLE predictions with the new GPT equation of state were found to be superior to predictions with the original group contributions with molecular equations. The modified equation can be used in systems of nalkanes and alcohols where data for molecular parameters are lacking. The proposed temperature dependence of the group interaction parameters improved predictions over a wide range of temperature and pressure.

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41

Hall, Christopher. "The coordination of alkanes to transition metal fragments." Thesis, University of York, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.331939.

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42

Bourdin, Vincent, Stefano Brandani, Alfeno Gunadi, Hervé Jobic, Cordula Krause, Jörg Kärger, and Wolfgang Schmidt. "Diffusion of n-alkanes in MFI-type zeolites." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-196416.

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43

Moses, Alvira. "Synthesis of surface active alkanes for cellulose modification." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/4874.

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119 leaves single sided printed, preliminary pages and numbered pages 1-101. Includes bibliography and a list of tables, figures, schemes and abbreviations. Digitized at 300 dpi (OCR), used Bizhub 250.
Thesis (MSc (Polymer Science))--University of Stellenbosch, 2006.
ENGLISH ABSTRACT: The properties and interactions of cellulose surfaces are of a great technical interest during papermaking and recycling. Sizing, the modification of fiber surfaces, e.g. with the purpose to reduce water penetration into the paper structure, plays an important role in obtaining paper with good printability and water resistance. Water resistance is the key end-property of paper being investigated in this study. Firstly a comparison was made between the degree of surface modification of cellulose by means of anionic, nonionic and reactive surfactants. The amount of surfactant adsorbed by the paperboard was determined and the paper surface evaluated via scanning electron microscopy (SEM). The sizing efficiency of the three industrial surfactants was evaluated in order to establish the surfactant structure best suited for sizing recycled paperboard. This was done via the Cobb test, an industrial method to measure water uptake by paper, and contact angle measurements. The reactive surfactant was found to have the best sizing efficiency and focus shifted to synthesizing selected copolymer surfactants via free radical copolymerization. Two copolymers were synthesized, with maleic anhydride as the polar part in both. Butyl methacrylate and lauryl methacrylate were selected as the hydrophobic parts in the respective copolymer systems. The unavailability of reactivity ratios for the respective copolymer systems led to the use of in situ proton nuclear magnetic resonance spectroscopy CH NMR) for the determination of the co-monomer incorporation in both copolymer systems. Quantitative 13C NMR spectroscopy was also employed in order to establish the co-monomer content of the isolated copolymers obtained during bench-scale (laboratory) experiments. Lastly, a comparison of the degree of surface modification of cellulose was made between that which was achieved with the industrial reactive surfactant and that with the two synthesized polymeric reactive surfactants. The two synthesized polymeric surfactants were found to have a better sizing efficiency than the industrial reactive surfactant, and the maleic anhydride-lauryl methacrylate copolymer system gave the best results.
AFRIKAANSE OPSOMMING: Die eienskappe en interaksies van sellulose-oppervlaktes is van groot tegniese belang gedurende die vervaardiging en hergebruik van papier. Oppervlakte behandeling, die modifikasie van vesel-oppervlaktes bv. met die doel om water indringing in die papierstruktuur te verminder, speel 'n belangrike rol in die daarstel van papier met goeie drukkwaliteit en waterweerstand. Waterweerstand is die sleuteleienskap van papier wat in hierdie werkstuk ondersoek word. Eerstens is daar 'n vergelyking getref tussen die verandering van sellulose-oppervlaktes deur middel van anioniese, nie-ioniese en reaktiewe sepe. Die hoeveelheid seep geabsorbeer deur die papierbord is bepaal en die papier-oppervlak ondersoek deur middel van skandeer-elektronmikroskopie (SEM). Die behandelingsdoeltreffendheid van die drie industriele sepe is ondersoek om vas te stel watter seep die beste struktuur het om hergebruikte papierbord effektief te behandel. Dit is gedoen deur middel van die Cobbtoets, 'n industriele metode om wateropname van papier te meet, asook kontakhoekmetings. Daar is gevind dat die reaktiewe seep die beste behandelingsdoeltreffendheid het en daar is vervolgens gekonsentreer op die bereiding van geselekteerde reaktiewe kopolimeersepe deur middel van vryeradikaalkopolimerisasie. Twee kopolimere is berei, met maleienanhidried as die polere gedeeite van albei. Butielmetakrilaat en laurielmetakrilaat is gekies vir die nie-polere gedeeltes van die onderskeie kopolimeersisteme. Die onbeskikbaarheid van reaktiwiteitsverhoudings vir die onderskeie kopolimeersisteme het gelei tot die gebruik van in situ proton kern magnetiese resonansie spektroskopie eH KMR) vir die bepaling van die ko-monomeer insluiting in beide kopolimeersisteme. Kwantitatiewe koolstofdertienkemmagnetieseresonansie spektroskopie (13C KMR) is ook gebruik om die ko-monomeerinhoud van die geisoleerde kopolimere, verkry tydens laboratoriumeksperimente, te bepaal. Laastens is 'n vergelyking getref tussen die graad van modifikasie van selluloseoppervlaktes deur middel van die industriele reaktiewe seep in vergelyking met die twee bereide polimeriese reaktiewe sepe. Daar is gevind dat die twee gesintetiseerde polimeriese sepe beter behandelingsdoeltreffendheid as die industriele reaktiewe seep het, met die maleienanhidried-laurielmetakrilaat-kopolimeersisteem wat die beste resultaat lewer.

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44

Schwarz, Cara Elsbeth. "The phase equilibrium of alkanes and supercritical fluids." Thesis, Stellenbosch : University of Stellenbosch, 2001. http://hdl.handle.net/10019.1/2532.

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Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2001.
Current methods for wax fractionation result in products with large polydispersity, and due to the high temperatures required, thermal degradation of the wax is often incurred. The need for an alternative process thus exists. The purpose of this project is to investigate the technical viability of supercritical fluid processing as an alternative wax fractionation technology. The main aims of this project are to select a suitable supercritical solvent, to conduct binary phase equilibrium experiments, to determine if the process is technically viable and to investigate the ability of various equations of state to correlate the phase equilibrium data. Based on limited data from the literature, propane and a propane rich LPG (Liquefied Petroleum Gas) were selected as suitable solvents. Literature data for propane and high molecular weight alkanes is scares and incomplete, thus necessitating experimental measurements. A phase equilibrium cell was designed, constructed and commissioned. The cell was designed for pressures up to 500 bar and temperatures to 200 oC, and with the aid of an endoscope, the phase transitions were detected visually. The measurements correspond well to literature values from reliable research groups. Phase equilibrium data sets for propane with nC32, nC36, nC38, nC40, nC44, nC46, nC54 and nC60 as well as LP Gas with nC36 were measured. At temperatures just above the melting point of the alkanes, the phase transition pressures can be considered to be moderate, which will positively impact the economics of the process. The phase transition pressure increases with increasing carbon number, the relationship being found to be linear when the pressure is plotted as a function of carbon number at constant mass fractions and temperature. The increase in phase transition pressure with increasing carbon number indicates that the solvent will be able to selectively fractionate the wax. At higher temperatures the gradient of the line is larger and may thus lead to improved selectivity. The higher temperatures will also lead to better mass transfer. The linear relationship indicates that limited extrapolation to higher carbon numbers may be possible. However, this needs to be verified experimentally. The inability to measure the critical point and vapour pressure curves of the higher molecular weight normal alkanes, as well as the inability of cubic equations of state to predict liquid volumes and to capture the chain specific effects such as internal rotations, results in cubic equations of state requiring large interaction parameters to fit the data. The alternative, statistical mechanical equations of state, have difficulty in predicting the critical point of the solvent correctly and thus overpredicts the mixture critical point, yet require smaller interaction parameters to fit the data. Further work is required to improve the predictability of these non-cubic equations of state. This project has proven that wax fractionation by supercritical extraction with propane is technically feasible.

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Du, Xian. "Catalysis for CO2 activation reactions with light alkanes." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:924c17f7-5b71-4e70-b304-e0686d0413ea.

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CO₂, without question, the most famous greenhouse gas, is known to have an increasing concentration in both the atmosphere and oceans. To slow down the pace not only of global warming but also the ocean acidification, several routes are proposed to effectively reduce the net emission of CO₂. Compared to Carbon Capture and Sequestration/Storage (CCS), Carbon Capture and Utilisation (CCU) has much more potential because of the lower costs of scale up and higher profitability to potentially attract capital investment. Different from the conventional CCU route which is to reduce CO₂ to fuels with hydrogen generated via renewable-energy-driving electricity, two processes are investigated in this thesis; that of Dry Methane Reforming (DMR) and the DeHydrogenation of Propane by CO₂ (DHP by CO₂). The projects on these two processes not only develop catalysts which would be suitable for the reaction performance, but also the ultimate aim is to link the processes with a renewable energy source (in the thesis we chose Solar Thermal Heating).Thermodynamic calculations and process simulations were also evaluated. The results of DMR unfortunately did not indicate a promising future to link with Solar Thermal Heating due to the very high temperature required during the process. However, the results of thermodynamic calculations and process simulations in DMR project illustrate a good opportunity to utilise flue gas in industry through the so-called Tri- Methane Reforming (TMR). In the DHP by CO₂ process, the catalysts developed were less promising than the ones in DMR due to the severe side-reactions occurred which significantly decreased the selectivity for the desired product. However - and importantly - through our thermodynamic calculations and process simulations, the DHP by CO₂ process has a bright future if the Solar Thermal Heating can be applied with the relative lower temperature requirement, making the CO₂ utilisation process much easier to be fulfilled than DMR.

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46

Wickramarachchi, P. A. S. R. "Vibrational spectroscopy of linear and branched long alkanes." Thesis, Sheffield Hallam University, 2006. http://shura.shu.ac.uk/20531/.

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In this work we studied monodisperse long chain alkanes as model compounds for semi crystalline polymers, using vibrational spectroscopy. The interest in vibrational spectroscopy is due to its sensitivity to both the crystalline structure and conformational disorder. We used the following vibrational techniques: Fourier transform infrared transmission, Fourier transform infrared - attenuated total reflection (FTIR-ATR), Raman spectroscopy and Inelastic neutron scattering (INS) spectroscopy. In addition, small angle X-ray scattering (SAXS) was used where necessary. In this study FTIR-ATR and INS techniques were not successful in the characterisation of long chain alkanes. A Raman spectroscopic method, based on conformationally sensitive vibrations, was established using a short chain n-alkane to identify solid-solid phase transitions and was applied to long chain alkanes. Using this method a transition to a non-integer form (NIF) form was identified in two 'Y-shaped' long chain alkane samples at similar temperatures as SAXS. One of these samples is partially deuterated (with deuterium end caps) while the other one is its hydrogenated analogue. However, the end-deuterated sample is not 100% end-deuterated due to a fault in the synthesis. Therefore, here we developed a FTIR-transmission method to determine the isotopic ratio in these partially deuterated alkane samples. Our calculations based on this method showed that the end deuterated 'Y-shaped' alkane only consists of 79.9% of the expected deuterium(D)/hydrogen(H) ratio. A SAXS study on a linear end-deuterated alkane showed that the chains achieve a maximum tilt of 35°, which is the most common tilt angle also for polyethylene. Combining these results with those from previous studies on the same sample, a relationship between chain perfecting and the chain tilt was established. It was found that the ordering of the crystal structure induces chain tilting in order to accommodate the incoming chain ends to the crystalline layer. The increase in the domain size during this process was found to be from 16 to more than 50 chains per domain. The attempt to explain the observed shift of the SAXS spacings in the tilting experiment, away from the positions predicted by Bragg's equation by using a paracrystalline model failed. Hence, we suggest a model with an asymmetric thickness distribution will be more appropriate in this regard. The simulated CD[2] bending vibration mode splitting of the infrared spectrum of the random fold model of this end-deuterated alkane is 9.0 cm[-1] whereas a maximum splitting of 9.1 cm[-1] is expected for this mode for a regular fold model of the same alkane. Therefore a vibrational spectroscopic differentiation between these two models based on the experimental CD[2] bending splitting is highly unlikely.

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47

Galassi, Giulio Roberto. "Monte Carlo simulations of diatomics, polymers and alkanes." Thesis, University of Southampton, 1993. https://eprints.soton.ac.uk/421719/.

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48

Xu, Wenjian. "Fluorination Effect on the Conformational Properties of Alkanes." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3103/.

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A Series of fluorophores of the general formular P(CF2)nP and P(CF2)n-1CF3 has been synthesized. Copper catalyzed coupling of 1-bromopyrene and the corresponding mono and di-iodoperfluoroalkanes were used in most cases. For the n=3 dimer, a novel 1,w-perfluoroalkylation of pyrene via bis-decarboxylation of hexafluorogultaric acid was utilized. These compounds, along with suitable hydrocarbon analogs, are being used to study the flexibility of fluorocarbon chains using emission. We have found that the excimer formation for the fluorinated pyrene monomers is highly dependent on concentration and is less efficient than for pyene. Excimer formation for the fluorinated pyrene dimers is much more efficient than for the fluorocarbon monomers and is only slightly concentraion dependent. Steady-state emission spectra indicate hydrocarbon dimers-models form excimers more efficiently than the fluorinated dimers suggesting the fluorinated chains are stiffer than the hydrocarbons. We conducted the temperature-dependent studies and quantified the conformational difference.

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Abudawood, Raed Hasan. "Hydroisomerization of alkanes over metal-loaded zeolite catalysts." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/hydroisomerization-of-alkanes-over-metalloaded-zeolite-catalysts(4511d50c-ff42-49e6-9a8a-d7ad88576bb1).html.

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Zeolite catalysis plays an important role in many industrial applications due to their unique properties and has become widely used in the area of oil refining. Of particular interest is Zeolite Y, which can be hydrothermally treated into its ultrastable form, USY. USY offers a superior practicality, especially when dealuminated and metal-loaded. The importance of alkanes hydroisomerization arises from the continuingly stricter regulations imposed on the utilization of gasoline as an automotive fuel. The requirements to reduce the aromatics content in gasoline present a need to find an alternative way to maintain its research octane number (RON). An alternative to gasoline's high-octane aromatic content is to increase the RON for the paraffinic content of gasoline, which can be accomplished through hydroisomerization. Commercially, bifunctional metal-loaded zeolites are used to hydroisomerize the light naphtha stream produced at overheads of atmospheric distillation towers. However, no such process exists for the low-value heavy naphtha cut. This targeted process would, if successful, greatly improve refiner's profitability.In this work, bifunctional USY zeolite catalysts are studied in the hydroisomerization of a normal alkane (nC7, RON = 0). This nC7, found in heavy naphtha, has been used as the 'model' compound. The impact of different reaction conditions and catalyst properties on catalyst activity and stability, in addition to the catalyst selectivity to high octane isomers is one step towards determining optimum conditions and preferential catalyst formulations that favour octane maximization. Six platinum-loaded USY zeolite catalysts, four in-house and two commercial, were tested in an atmospheric glass fixed-bed reactor and a stainless steel reactor purpose-built during the course of this thesis. Reaction temperatures ranged from 170 to 250oC at pressures between 1 and 15 bar. The hydrogen to hydrocarbon molar ratio was fixed at 9, with feed space time ranging from 35.14 to 140.6 kg.s/mol. In-house catalysts were hydrothermally treated at different severities, while commercial ones were originally dealuminated through acid-leaching treatments.Results have shown commercial catalyst CBV-712 gave the best performance and highest octane values for product isomers (>30). In addition, there was no coke generation. The next best catalyst was the most severely steamed in-house catalyst (USY-D) that has shown a remarkable performance at high pressures, almost eclipsing the performance of CBV-712, yet produced higher levels of coke. Other USY catalysts tested were less robust during reactions, probably due to imbalance in their acidic to metallic functions, or diffusion limitations arising from their pore structures. The best catalysts were, nonetheless, highly sensitive to sulfur presence in the feed, which severely impacted their activity, especially their metallic functions, and thus require sulfur-free feeds in order to demonstrate their full capacities. Simple kinetic modelling of experimental data was performed using the initial rates method and estimation of kinetic parameters, whose values were in good agreement with previous literature.

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Tsomis, Georgios. "Zusammenschau der frühgriechischen monodischen Melik (Alkaios, Sappho, Anakreon) /." Stuttgart : F. Steiner, 2001. http://catalogue.bnf.fr/ark:/12148/cb37659021j.

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Dissertations / Theses on the topic 'Alkanol'

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