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Dissertations / Theses on the topic 'Methane'

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Published: 4 June 2021
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1

Squire, Gavin Daniel. "Partial oxidation of methane to methanol and formaldehyde." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278072.

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2

Chellappa, Anand S. "Methane conversion to methanol : homogeneous and catalytic studies /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9842517.

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3

Matthews, Terry. "The Partial Oxidation of Methane to Methanol & Formaldehyde." TopSCHOLAR®, 1987. https://digitalcommons.wku.edu/theses/2602.

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The conversion of methane into methanol is viewed as one approach to utilizing the vast reserves of natural gas. One such prospect for the utilization of natural gas is the partial oxidation of methane to methanol. Methanol ranks high on the commodity market. As a liquid it is easily transportable and therefore skirts the issue of vast amounts of a gas having to be transported either by pipeline or by liquifying. The catalytic partial oxidation of methane to methanol is investigated. Two different reactor systems are employed. The first system is a fixed bed system. The second is a fluid bed system. Areas to be addressed are different catalyst systems, different loading rates, elemental promotion, different supports, surface area, catalyst particle mesh size, and effects of preparation.
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4

Afonso, Joana da Costa Franco. "Catalytic hydrogenation of carbon dioxide to form methanol and methane." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10854.

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5

Olsson, Susanna. "Dynamics of a spin-forbidden reaction transforming methane to methanol." Thesis, Uppsala universitet, Institutionen för kemi - BMC, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-385895.

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6

Borchardt, Lars, Winfried Nickel, Mirian Casco, Irena Senkovska, Volodymyr Bon, Dirk Wallacher, Nico Grimm, Simon Krause, and Joaquín Silvestre-Albero. "Illuminating solid gas storage in confined spaces – methane hydrate formation in porous model carbons." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-221847.

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Methane hydrate nucleation and growth in porous model carbon materials illuminates the way towards the design of an optimized solid-based methane storage technology. High-pressure methane adsorption studies on pre-humidified carbons with well-defined and uniform porosity show that methane hydrate formation in confined nanospace can take place at relatively low pressures, even below 3 MPa CH4, depending on the pore size and the adsorption temperature. The methane hydrate nucleation and growth is highly promoted at temperatures below the water freezing point, due to the lower activation energy in ice vs. liquid water. The methane storage capacity via hydrate formation increases with an increase in the pore size up to an optimum value for the 25 nm pore size model-carbon, with a 173% improvement in the adsorption capacity as compared to the dry sample. Synchrotron X-ray powder diffraction measurements (SXRPD) confirm the formation of methane hydrates with a sI structure, in close agreement with natural hydrates. Furthermore, SXRPD data anticipate a certain contraction of the unit cell parameter for methane hydrates grown in small pores.
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7

Prince, Bruce M. "The Mechanisms of Methane C–H Activation and Oxy-insertion Via Small Transition Metal Complexes: a DFT Computational Investigation." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500116/.

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Our country continues to demand clean renewable energy to meet the growing energy needs of our time. Thus, natural gas, which is 87% by volume of methane, has become a hot topic of discussion because it is a clean burning fuel. However, the transportation of methane is not easy because it is a gas at standard temperature and pressure. The usage of transition metals for the conversion of small organic species like methane into a liquid has been a longstanding practice in stoichiometric chemistry. Nonetheless, the current two-step process takes place at a high temperature and pressure for the conversion of methane and steam to methanol via CO + H2 (syngas). The direct oxidation of methane (CH4) into methanol (CH3OH) via homogeneous catalysis is of interest if the system can operate at standard pressure and a temperature less than 250 C. Methane is an inert gas due to the high C-H bond dissociation energy (BDE) of 105 kcal/mol. This dissertation discusses a series of computational investigations of oxy-insertion pathways to understand the essential chemistry behind the functionalization of methane via the use of homogeneous transition metal catalysis. The methane to methanol (MTM) catalytic cycle is made up of two key steps: (1) C-H activation by a metal-methoxy complex, (2) the insertion of oxygen into the metal−methyl bond (oxy-insertion). While, the first step (C-H activation) has been well studied, the second step has been less studied. Thus, this dissertation focuses on oxy-insertion via a two-step mechanism, oxygen-atom transfer (OAT) and methyl migration, utilizing transition metal complexes known to activate small organic species (e.g., PtII and PdII complexes). This research seeks to guide experimental investigations, and probe the role that metal charge and coordination number play.
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8

York, Andrew P. E. "Methane conversion chemistry." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334954.

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9

Hammond, Charles Rhodri. "Partial oxidation of methane to methanol using modified mixed metal oxides." Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/54537/.

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The current steam reforming process for the production of CH3OH is complicated and difficult, and therefore the direct partial oxidation of CH4 to CH3OH would be economically desirable. In previous work a design approach for a selective partial oxidation catalyst has been investigated, which comprises the combination of components with a desired reactivity, producing a successful selective partial oxidation catalyst. In this approach, it is considered a successful partial oxidation catalyst must activate methane, activate oxygen and not destroy the desired product, methanol. All these properties could not be found in a single catalyst, so it was proposed that two synergistic components could be combined, one responsible for methane activation and the other for oxygen activation/insertion. Previous work has studied the CH4/D2 exchange reaction as an indication of the ability of a metal oxide surface to activate CH4. Two metal oxides demonstrated appreciable activity for the activation of CH4, these being Ga2C3 and ZnO. These oxides were then doped with different metals in order to try and increase the activity of the catalyst. The doping of Ga2O3 with Zn or Mg did not improve the methane oxidation properties of Ga2C3, and the doping of ZnO with Ga significantly lowered the light off temperature, the temperature at which CH4 was first detected, and increased its oxidative capacity. The addition of precious metals significantly affected the catalysts ability to activate CH4. The addition of Au to the Ga and Zn catalysts dramatically reduced the light off temperature, and increased its rate of oxidation at lower temperatures, with the optimum loading 2% for both catalysts. For GaO(OH) and ZnO, the addition of 1%Au and l%Pt by coprecipitation produced a synergistic effect, producing lower light offs and higher CH4 conversion than the singly doped catalysts with Au and Pt separately. When the methane activation catalysts were combined with MoO3 in a physical mixture, a number of the mixtures produced higher methanol per pass percentage yields than its constituent parts. It is concluded that the increased methane activation properties beneficially interact with the oxygen activation and insertion properties of MoO3. However, none of the yields reported were significantly higher. A dual bed system, with the lower layer comprising the methane activation catalysts, and the upper layer consisting of MoO 3 was tested. The results for this system were promising, with the low temperature activation of CH4, combined with the oxygen insertion ability of MoO3, producing high selectivities of CH3OH at much lower temperatures. The best results were obtained when the ratio of the two layers was 50:50 with respect to 2%Au ZnO and MoO3. In previous work a design approach for a selective partial oxidation catalyst has been investigated, by combining components with a desired reactivity to produce a successful selective partial oxidation catalyst, which must activate methane and oxygen, and not destroy methanol. All these properties could not be found in a single catalyst, so it was proposed that two synergistic components could be combined, one responsible for methane activation and the other for oxygen activation/insertion. The doping of ZnO with Ga significantly lowered the light off temperature, and increased its oxidative capacity, an effect which was not seen with the doping of Ga2O3 with Zn or Mg. The addition of Au to the Ga and Zn catalysts dramatically reduced the light off temperature, and increased its rate of oxidation at lower temperatures, both with optimum loading of 2%. The addition of l%Au and l%Pt produced a synergistic effect, producing lower light offs and higher CH4 conversion than the singly doped catalysts with Au and Pt separately. When the methane activation catalysts were combined with MoO3 in a physical mixture, a number of the mixtures produced higher methanol per pass percentage yields than its constituent parts. It is concluded that the increased methane activation properties beneficially interact with the oxygen activation and insertion properties of MoO3. The dual bed system, with the lower layer comprising the methane activation catalysts, and the upper layer consisting of MoO 3 produced promising results, with the low temperature activation of CH4, combined with the oxygen insertion ability of MoO3, producing high selectivities of CH3OH at much lower temperatures. The best results were obtained when the ratio of the two layers was 50:50 with respect to 2%Au ZnO and MoO3. (Abstract shortened by UMI.).
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10

Borchardt, Lars, Winfried Nickel, Mirian Casco, Irena Senkovska, Volodymyr Bon, Dirk Wallacher, Nico Grimm, Simon Krause, and Joaquín Silvestre-Albero. "Illuminating solid gas storage in confined spaces – methane hydrate formation in porous model carbons." Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30232.

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Methane hydrate nucleation and growth in porous model carbon materials illuminates the way towards the design of an optimized solid-based methane storage technology. High-pressure methane adsorption studies on pre-humidified carbons with well-defined and uniform porosity show that methane hydrate formation in confined nanospace can take place at relatively low pressures, even below 3 MPa CH4, depending on the pore size and the adsorption temperature. The methane hydrate nucleation and growth is highly promoted at temperatures below the water freezing point, due to the lower activation energy in ice vs. liquid water. The methane storage capacity via hydrate formation increases with an increase in the pore size up to an optimum value for the 25 nm pore size model-carbon, with a 173% improvement in the adsorption capacity as compared to the dry sample. Synchrotron X-ray powder diffraction measurements (SXRPD) confirm the formation of methane hydrates with a sI structure, in close agreement with natural hydrates. Furthermore, SXRPD data anticipate a certain contraction of the unit cell parameter for methane hydrates grown in small pores.
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11

Modibedi, Remegia Mmalewane. "The catalytic membrane reactor for the conversion of methane to methanol and formaldehyde under mild conditions." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&amp.

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This thesis described the development of new catalytic system for the conversion of natural gas (methane) to liquid products such as methanol and formaldehyde. This technology can allow the exploitation of small and medium size gas fields without the need to build an expensive gas to liquid plants or long pipelines. The technology is based on a concept of non-separating membrane reactor where an inorganic membrane paper serves as a catalyst support through which a reaction mixture is flowing under mild conditions and short residence times.
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12

Gilmore, Rory Alan John. "Developing water and methane potentials for MD simulations of methane clathrate hydrate." Thesis, Queen Mary, University of London, 2018. http://qmro.qmul.ac.uk/xmlui/handle/123456789/41787.

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The aim of this thesis is to develop a set of intermolecular potentials that enable the study of nucleation or decomposition of methane hydrates. The potentials are developed for water, methane, and the water-methane pair by fitting to SAPT(DFT) reference energies. The first set of potentials developed differ from recent polarisable models in that they have rank 4 ISA multipoles, rank 3 anisotropic polarisabilities, rank 3 isotropic dispersion, and anisotropic exchange-repulsion terms. These potentials are validated based on the structures and energies of small clusters and second virial coefficients. The potentials are then significantly simplified for use in MD simulations with DL_POLY4. Simplifying the methane potential makes it difficult to fit simultaneously the global minimum dimer and a set of randomly generated dimers used as reference energies. Several methods are tested to account for polarisation in water within the limitations of DL_POLY and it is found that for MD simulations good results can be attained by increasing the charge values to match the multipole moments of a water molecule in a dielectric. Simulations are carried out for liquid water, ice Ih, and methane gas to validate the new models. The models developed are compared in MD simulations with TIP4P/Ice and the United Atom Methane (UAM) model in simulations of sI methane clathrate; both under stable conditions and while undergoing decomposition at different temperatures. It is found that the melting behaviour differs according the methane- and water-methane interactions; the behaviour of methane under clathrate decomposition using either methane model is discussed.
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13

Thevenin, Philippe. "Catalytic combustion of methane." Doctoral thesis, KTH, Chemical Engineering and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3402.

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Catalytic combustion is an environmentally benign technologywhich has recently reached the stage of commercialization.Palladium is the catalyst of choice when considering gasturbines fuelled with natural gas because of its superioractivity for methane oxidation. Several fundamental issues arestill open and their understanding would result in animprovement of the technology. Hence, the work presented inthis thesis aims at the identification of some of theparameters which govern the combustion activity ofpalladium-based catalysts.

The first part of this work gives a background to catalyticcombustion and a brief comparison with other existingtechnologies. Paper I reviews some of the issues related tomaterial development and combustor design.

The second part of this thesis consists of an experimentalinvestigation on palladium-based catalysts. The influence ofthe preparation method onthe properties of these catalystmaterials is investigated in Paper II. Paper III examines theactivity of the following catalysts: Pd/Al2O3, Pd/Ba-Al2O3 andPd/La-Al2O3. Specific attention is given to the metal-supportinteraction which strongly affects the combustion activity ofpalladium. The effect of doping of the support by addition ofcerium is reported in Paper IV.

Finally, the deactivation of combustion catalysts isconsidered. The various deactivation processes which may affecthigh temperature combustion catalysts are reviewed in Paper V.Paper VI focuses on the poisoning of supported palladiumcatalysts by sulphur species. Palladium exhibits a higherresistance to sulphur poisoning than transition metals.Nevertheless, the nature of the support material plays animportant role and may entail a severe loss of activity whensulphur is present in the fuel-air mixture entering thecombustion chamber.

Keywords: catalytic combustion, gas turbine, methane,palladium, alumina, barium, lanthanum, oxidation, preparation,temperature-programmed oxidation (TPO), decomposition,reoxidation, X-ray photoelectron spectroscopy (XPS),metal-support interaction, deactivation, sulphur, poisoning.The cover illustration is a TEM picture of a 100 nm palladiumparticle supported on alumina

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14

Kinjet, Marc Philip. "Methane production from cows." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273714.

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15

Narsimhan, Karthik. "Catalytic, low temperature oxidation of methane into methanol over copper-exchanged zeolites." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/109671.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 135-147).
As production of shale gas has increased greatly in the United States, the amount of stranded shale gas that is flared as carbon dioxide has become significant enough to be considered an environmental hazard and a wasted resource. The conversion of methane, the primary component of natural gas, into methanol, an easily stored liquid, is of practical interest. However, shale wells are generally inaccessible to reforming facilities, and construction of on-site, conventional methanol synthesis plants is cost prohibitive. Capital costs could be reduced by the direct conversion of methane into methanol at low temperature. Existing strategies for the partial oxidation of methane require harsh solvents, need exotic oxidizing agents, or deactivate easily. Copper-exchanged zeolites have emerged as candidates for methanol production due to high methanol selectivity (> 99%), utilization of oxygen, and low reaction temperature (423-473 K). Despite these advantages, three significant shortcomings exist: 1) the location of surface intermediates on the zeolite is not well understood; 2) methane oxidation is stoichiometric, not catalytic; 3) there are few active sites and methanol yield is low. This work addresses all three shortcomings. First, a new reaction pathway is identified for methane oxidation in copper-exchanged mordenite zeolites using tandem methane oxidation and Koch carbonylation reactions. Methoxy species migrate away from the copper active sites and adsorb onto Bronsted acid sites, signifying spillover on the zeolite surface. Second, a process is developed as the first instance of the catalytic oxidation of methane into methanol at low temperature, in the vapor phase, and using oxygen as the oxidant. A variety of commercially available copper-exchanged zeolites are shown to exhibit stable methanol production with high methanol selectivity. Third, catalytic methanol production rates and methane conversion are further improved 100- fold through the synthetic control of copper speciation in chabazite zeolites. Isolated monocopper species, directed through the one-pot synthesis of copper-exchanged chabazite zeolites, correlates with methane oxidation activity and is likely the precursor to the catalytic site. Together, these synthetic methods provide guidelines for catalyst design and further improvements in catalytic activity.
by Karthik Narsimhan.
Ph. D.
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16

Taylor, Stuart Hamilton. "The design of new catalysts for the partial oxidation of methane to methanol." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260339.

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The direct partial oxidation of CH4 to CH30H would offer considerable economic advantages over the current two stage process. It would also facilitate the utilisation of natural gas reserves in remote locations. To date, the catalytic partial oxidation of CH4 to CH30H has been extensively studied, however, it has proved to be an extremely demanding reaction which has met with little success. This study has adopted a design approach for the identification of new catalysts by considering the efficacy of single oxides for CH4 activation, CH30H oxidation and 02 isotope exchange activity. On the basis of CH30H stability Sb203 was the best oxide, showing only 3 % CH30H conversion at 500°C. The majority of oxides totally combusted CH30H below 400°C. Mo03, Nb20S, Ta20S and W03 showed high selectivity to HCHO and (CH3hO with low levels of COx throughout the range of conversion. These oxides were not considered unsuitable from the perspective of CH30H stability as the products HCHO and (CH3hO are not considered undesirable by products from a CH4 partial oxidation process. A weak but significant correlation was observed between the combustion activity of the oxides and the oxygen exchange rate. Using CH4/D2 exchange as an indication of CH4 activation it has been shown that Ga203 was a particularly good catalyst, followed by ZnO and Cr203. A relationship between exchange activity and oxide basicity was established for the rare earth sesquioxides, MgO and CaO. This relationship indicak:d that CH4 activation took place by H+ abstraction to form a surface CH3- species. From these results and literature studies of oxygen isotope exchange, dual component oxides have been formulated as catalysts for CH4 partial oxidation. The best catalysts was Ga203/Mo03, prepared by a physical mixing process. This catalyst showed an increased yield of CH30H over the homogeneous gas phase oxidation of CH4 in a quartz chips packed reactor. This increased yield has been attributed to the development of a cooperative effect between the two component oxides. Comparison of the catalytic data with the homogeneous reaction in the empty reactor tube showed that the presence of a catalyst had a detrimental effect on the CH30H yield.
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17

Hamdan, Abdullah. "Infrared spectroscopy of methane dimer." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=978829921.

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18

Galbraith, Jayson Kent. "Methane production in native ruminants." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq22596.pdf.

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19

El, Solh Tarek. "Heterogeneous catalyst for methane reforming." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/MQ30748.pdf.

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20

Mann, Kenneth R. C. "Premixed ammonia-methane-air combustion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ62250.pdf.

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21

Kumarasamy, Puvaneswary. "Heterogeneous catalysis for methane oxidation." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326890.

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22

Ashcroft, Alexander T. "Methane conversion over oxide catalysts." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305983.

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23

Wang, David Texan. "The geochemistry of methane isotopologues." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111690.

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Thesis: Ph.D. in Geochemistry, Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 123-143).
This thesis documents the origin, distribution, and fate of methane and several of its isotopic forms on Earth. Using observational, experimental, and theoretical approaches, I illustrate how the relative abundances of ¹²CH₄, ¹³CH₄, ¹²CH₃D, and ¹³CH₃D record the formation, transport, and breakdown of methane in selected settings. Chapter 2 reports precise determinations of ¹³CH₃D, a "clumped" isotopologue of methane, in samples collected from various settings representing many of the major sources and reservoirs of methane on Earth. The results show that the information encoded by the abundance of ¹³CH₃D enables differentiation of methane generated by microbial, thermogenic, and abiogenic processes. A strong correlation between clumped- and hydrogen-isotope signatures in microbial methane is identified and quantitatively linked to the availability of H₂ and the reversibility of microbially-mediated methanogenesis in the environment. Determination of ¹³CH₃D in combination with hydrogen-isotope ratios of methane and water provides a sensitive indicator of the extent of C-H bond equilibration, enables fingerprinting of methane-generating mechanisms, and in some cases, supplies direct constraints for locating the waters from which migrated gases were sourced. Chapter 3 applies this concept to constrain the origin of methane in hydrothermal fluids from sediment-poor vent fields hosted in mafic and ultramafic rocks on slow- and ultraslow-spreading mid-ocean ridges. The data support a hypogene model whereby methane forms abiotically within plutonic rocks of the oceanic crust at temperatures above ca. 300 °C during respeciation of magmatic volatiles, and is subsequently extracted during active, convective hydrothermal circulation. Chapter 4 presents the results of culture experiments in which methane is oxidized in the presence of O₂ by the bacterium Methylococcus capsulatus strain Bath. The results show that the clumped isotopologue abundances of partially-oxidized methane can be predicted from knowledge of ¹³C/¹²C and D/H isotope fractionation factors alone.
by David Texan Wang.
Ph.D. in Geochemistry
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24

He, Li. "Catalytic Methane Combustion in Microreactors." Thesis, Nantes, 2020. http://www.theses.fr/2020NANT4026.

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La thèse actuelle traite de la combustion catalytique du méthane dans des micro réacteurs à catalyseur Pt/γ-Al2O3 à revêtement mural. La préparation de la couche de lavage Pt/γ-Al2O3, les systèmes de revêtement catalytique monocouche et multicouche et les différentes conceptions de géométries des micro réacteurs ont été particulièrement étudiés. Divers aspects ont ainsi été abordés, y compris les procédures de préparation du revêtement de catalyseur (par exemple, les propriétés du liant, la valeur de pH, la taille de particule initiale d' Al2O3), l'optimisation de différentes conditions de réaction avec des systèmes de revêtement monocouche et multicouche (par exemple, température, débit, rapport molaire O2/CH4, charge de Pt et épaisseur de revêtement), l'effet des configurations de canaux internes dans le micro réacteur (c'est-à-dire impliquant des canaux parallèles droits, une cavité, des canaux doubles serpentins, des canaux parallèles obstrués, un circuit maillé et un réseau vasculaire) sur les performances de réaction
The current thesis deals with the catalytic methane combustion in microreactors with wall-coated Pt/γ-Al2O3 catalyst. The Pt/γ-Al2O3 washcoat preparation, the single- and multi-layer catalytic coating systems, and the different designs of microreactor geometries were particularly investigated. Various aspects were thus addressed, including the preparation procedures of the catalyst coating (e.g., the binder properties, pH value, initial Al2O3 particle size), the optimization of different reaction conditions with single- and multi-layer coating systems (e.g., temperature, flow rate, O2/CH4 molar ratio, Pt loading and coating thickness), the effect of internal channel configurations in the microreactor (i.e., involving straight parallel channels, cavity, double serpentine channels, obstacled parallel channels, meshed circuit and vascular network) on the reaction performance
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25

Penteado, Paulo Fernando. "Study of Titan's Methane Cycle." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194314.

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We developed radiative transfer models to reproduce Titan’s visible and near infrared spectra, to determine the effects of the haze, and retrieve the methane abundances during Titan’s current southern summer. With ground-based high resolution spectra of CH3D absorption at 1.6 μm, we measured the global CH₃D abundance. Combined with observations of 8.6 μm emission of CH₃D and CH₄ that indicate their relative abundances, we thus determined the global CH₄ abundance. We expanded on these ground-based measurements, with improved radiative transfer models based on the Huygens DISR models, and spectra which resolve the spatial variation of the CH₃D lines. The profiles of CH3D thus obtained revealed that the methane abundance on the lowest 10 km of Titan’s atmosphere does not vary by more than 20% over 32°S-32°N. With the extensive coverage of Cassini VIMS observations at 0.35-1.6 μm, we determined the latitudinal variation of the methane at 20-50 km and of the haze. We find an ambiguity between the methane and haze abundances, so their gradients become coupled. At the lower limit of the methane gradient, the spectral variation observed can be reproduced with no methane change, and a haze density increase of 60% between 20°S and 10°S. The largest methane variation allowed by the data, derived assuming no haze variation with latitude, is a drop of 60% over latitudes 27°S to 19°N. Our analysis indicates that the latitudinal variations in Titan’s visible to near-IR albedo, the North/South Asymmetry, result primarily from variations in the thickness of the haze above 80 km altitude. The range of methane latitudinal variations allowed between 27°S to 19°N indicates temperature variations of no more than 1.5 K at 20-30 km, altitudes where the Huygens profile is saturated.
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26

Wallar, Bradley James. "Probing the interactions between component B and the hydroxylase of methane monooxygenase /." Diss., ON-CAMPUS Access For University of Minnesota, Twin Cities Click on "Connect to Digital Dissertations", 2000. http://www.lib.umn.edu/articles/proquest.phtml.

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27

Balan, Huseyin Onur. "Modeling The Effects Of Variable Coal Properties On Methane Production During Enhanced Coalbed Methane Recovery." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609622/index.pdf.

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Most of the coal properties depend on carbon content and vitrinite reflectance, which are rank dependent parameters. In this study, a new approach was followed by constructing a simulation input database with rank-dependent coal properties published in the literature which are namely cleat spacing, coal porosity, density, and parameters related to strength of coal, shrinkage, swelling, and sorption. Simulations related to enhanced coalbed methane (ECBM) recovery, which is the displacement of adsorbed CH4 in coal matrix with CO2 or CO2/N2 gas injection, were run with respect to different coal properties, operational parameters, shrinkage and swelling effects by using a compositional reservoir simulator of CMG (Computer Modeling Group) /GEM module. Sorption-controlled behavior of coalbeds and interaction of coal media with injected gas mixture, which is called shrinkage and swelling, alter the coal properties controlling gas flow with respect to injection time. Multicomponent shrinkage and swelling effects were modeled with extended Palmer and Mansoori equation. In conclusion, medium-volatile bituminous coal rank, dry coal reservoir type, inverted 5-spot pattern, 100 acre drainage area, cleat permeability from 10 to 25 md, CO2/N2 molar composition between 50/50 % and 75/25 %, and drilling horizontal wells rather than vertical ones are better selections for ECBM recovery. In addition, low-rank coals and dry coal reservoirs are affected more negatively by shrinkage and swelling. Mixing CO2 with N2 prior to its injection leads to a reduction in swelling effect. It has been understood that elastic modulus is the most important parameter controlling shrinkage and swelling with a sensitivity analysis.
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28

Maråk, Knut Arild. "Condensation Heat Transfer and Pressure Drop for Methane and Binary Methane Fluids in Small Channels." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-5702.

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A conventional heat exchanger consists of fluid channels with diameter larger than approximately 3 mm. Here, the phenomena around heat transfer and pressure drop are more or less well understood and can be well predicted. Newer and more compact heat exchangers use channels with smaller diameter which gives multiple advantages; they occupy less volume, are lighter, may be modular and can be faster and cheaper to produce. However, it is uncertain whether the phenomena affecting heat transfer and pressure drop are the same as in the larger channels. Clarifying this with respect to possible usage in the LNG-industry has been the main purpose of this work. An experimental set-up designed by Dr. Steffen Grohmann has been used in these investigations. A total of 749 measurements in tubes with diameter 1 mm, 0.5 mm and 0.25 mm have been done. Both single and two-phase flow measurements of pure methane, methane/ethane- and methane/nitrogenmixtures have been carried out. The measurements were done over a broad range with respect to pressure, vapour fraction, mass flux and heat flux. Also the pressure drop was measured. The conclusion is that the models concerning heat transfer and pressure drop in conventional channels also can be used in tubes with diameter 1 mm and 0.5 mm. The results from the 0.25 mm tube are burdened with too high uncertainty to be used in the conclusion. The results can also be relevant for non-circular diameters in microscale, e.g. for plate-fin heat exchangers.
Konvensjonelle varmevekslarar nyttar kanalar med diameter ned til omlag 3 mm. I desse er fenomena kring varmeovergang og trykktap i stor grad kjende. Nyare og meir kompakte varmevekslarar har kanalar med mindre diameter som inneber ei rekkje fordelar; dei tek mindre plass, er lettare og kan vere raskare og billigare å produsere. Det herskar imidlertid uvisse om fenomena kring varmeovergang og trykktap er dei same som i konvensjonelle kanalar. Å få dette avklart i høve til mogleg bruk i LNG-industrien har vore hovudføremålet med arbeidet. Eit eksperimentelt oppsett designa av Steffen Grohmann vart brukt i undersøkjingane. Tilsaman 749 m˚alingar i røyr med diameter 1 mm, 0.5 mm og 0.25 mm vart utført. Både einfase kjøling og kondensasjon av metan og blandingar av metan/etan og metan/nitrogen vart gjort. Målingane varierte over eit stort omr˚ade med omsyn til trykk, dampfraksjon, massefluks og varmefluks. Ogs˚a trykkfall gjennom røyra vart målt. Resultata viser at varmeovergang i einfase veske kan forutseiast med eksisterande modellar i 1 mm og 0.5 mm røyra. Trykkfallsmålingane for 1 mm royret er som forventa utifr˚a konvensjonelle modellar. For 0.5 mm røyret er trykkfallet høgare enn forventa. For 0.25-mm røyret er uvissa for stor til at resultata kan brukast i ein konklusjon. For kondensering av rein metan kan varmeovergangen i 1 mm-røyret forutseiast med konvensjonelle modellar. I 0.5 mm røyret er varmeovergangen høgare enn berekna. For kondensering av binære blandingar kan varmeovergangen bereknast med konvensjonelle modellar for både 1 mm og0.5 mm royret. For tofasemålingar i 1 mm-røyret er den gjennomsnittlege uvissa for varmeovergang rundt 10 % og hovudsakleg knytt til temperatursensorane. For 0.5 mm røyret er uvissa for kondensering av rein metan litt over 20 %, medan den er rundt 10 % for kondensering av binarblandingane. For 0.5 mm-royet og sarskilt for 0.25 mm-røyret er massestraumsmålaren ei mykje viktigare kjelde til uvisse.
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29

Hayes, Jonathan George. "The Methane Range: Coalbed Methane Development, Sage-Grouse protection, and The Ranching Way of Life." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-12192008-143539/.

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Coalbed methane development has proliferated across much of the western United States. Campbell County, Wyoming, in the Powder River Basin is one area that has seem some of the highest amounts of this development, most of it occurring on land where the surface use is livestock grazing, resulting in conflicts over resource use. This thesis takes a grounded theory approach to understanding the meaning that the ranchers that operate on this land have attached to this development. In doing so, this paper argues that these ranchers form opinions and attitudes based on how CBM has affected the ranching way of life and not simply on the perceived opportunity for economic gain. It also argues that although objections raised by this population to the listing the Greater Sage-Grouse as an endangered species are largely framed as objections to the way in which scientific conclusions are drawn, this may be more representative of embedded cultural viewpoints thereby making efforts to resolve this conflict through further scientific research, futile. This paper concludes that a more collaborative approach to issues surrounding CBM may have helped to avoid much of the conflict that characterizes this issue.
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30

McMahon, Sean. "Mars, methane and microbes : deep biospheres and other sources of methane on Earth and Mars." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=214837.

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This thesis reports the application of geological techniques to astrobiological questions about hydrogen-consuming, methane-producing life in planetary crusts, particularly on Earth and Mars. I report original contributions to the following areas of knowledge: (1) the size of Earth's continental deep biosphere; (2) the effect of subsurface habitability on circumstellar habitable zones; (3) the habitability of martian vesicular basalt; (4) the role of methane clathrates in “Snowball Earth” deglaciation; (5) the retention of methane by rocks and minerals, with implications for deep habitats on Earth and Mars, and sampling techniques adaptable for Mars missions; (6) the volatile content of martian meteorites, with implications for life; and (7) sources of hydrogen for subsurface life or abiotic methanogenesis on Earth and Mars.
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31

Boulart, Cedric. "Methane in deep sea hydrothermal plumes : development of a new in-situ methane sensing technology." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/65667/.

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Information on the concentration and distribution of dissolved methane (CH4), together with other geochemical tracers, in real time is of great value in detecting, monitoring, and understanding the functioning of hydrothermal plumes. Water column anomalies of light transmission, dissolved CH4, manganese (Mn), and iron (Fe) were located over segments 15 and 16 of the Central Indian Ridge (CIR 20ºS), in December 2006. Along segment 15, a hydrothermal plume was present at 19°33’S/65°50’E. The source might be located north of that position and dispersed along the western flank by NW-SE currents. Methane to manganese ratios suggest that methane is produced by magmatic processes. On Segment 16, evidence for 1 or 2 hydrothermal plumes were detected over a lava plain (18°20’S/65°18’E). These data suffered from uncertainties due to sampling issues, which demonstrate the need for a reliable in-situ methane sensing technology. Current in-situ methane sensing technology is based on gas partitioning across gas permeable membranes, which are poorly characterised and variable in terms of permeability and environmental pressures. Two optical techniques were laboratory tested for the measurement of dissolved methane; Near Infrared Fibre-optic Evanescent Wave Spectroscopy (FEWS) and Surface Plasmon Resonance (SPR). No detection (at the µM level) was possible with FEWS, but the second technique using SPR sensors associated with a methane specific binding chemically showed great promise. A limit of detection of 0.2 nM and a linear concentration range from 1 to 300 nM was demonstrated, under a range of temperature and salinity. In-situ deployments confirmed the suitability of the method for in-situ measurements. Values given by the sensor correlated well with the concentrations measured by traditional techniques. Future work is needed to decrease instrumental noise and to reduce the response time, and associated hysteresis effect.
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32

Miyajima, Yusuke. "Origin of methane at ancient methane seeps inferred from organic geochemical signatures in seep carbonates." Kyoto University, 2018. http://hdl.handle.net/2433/232261.

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33

Randall, William Sanford. "How Methane Made the Mountain: The Material Ghost and the Technological Sublime in Methane Ghosts." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1460722538.

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34

Hayes, Jonathan George. "The methane range coalbed methane development, sage-grouse protection, and the ranching way of life /." [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-12192008-143539/unrestricted/TheMethaneRange.pdf.

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Thesis (M.S.) -- University of Montana, 2008.
Title from author supplied metadata. Description based on contents viewed on June 20, 2009. ETD number: etd-12192008-143539. Includes bibliographical references.
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35

Storch, Henrik von Verfasser], Bernhard [Akademischer Betreuer] Hoffschmidt, and André [Akademischer Betreuer] [Bardow. "Methanol production via solar reforming of methane / Henrik von Storch ; Bernhard Hoffschmidt, André Bardow." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1126040878/34.

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36

Thorn, Garrick J. S. "Development of an Immobilized Nitrosomonas europaea Bioreactor for the Production of Methanol from Methane." Thesis, University of Canterbury. Chemical and Process Engineering, 2006. http://hdl.handle.net/10092/1867.

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This research investigates a novel approach to methanol production from methane. The high use of fossil fuels in New Zealand and around the world causes global warming. Using clearer, renewable fuels the problem could potentially be reduced. Biomass energy is energy stored in organic matter such as plants and animals and is one of the options for a cleaner, renewable energy source. A common biofuel is methane that is produced by anaerobic digestion. Although methane is a good fuel, the energy is more accessible if it is converted to methanol. While technology exists to produce methanol from methane, these processes are thermo-chemical and require large scale production to be economic. Nitrosomonas europaea, a nitrifying bacterium, has been shown to oxidize methane to methanol (Hyman and Wood 1983). This research investigates the possibility of converting methane into methanol using immobilized N. europaea for use in smaller applications. A trickle bed bioreactor was developed, containing a pure culture of N. europaea immobilized in a biofilm on ceramic raschig rings. The reactor had a biomass concentration of 7.82 ± 0.43 g VSS/l. This was between 4 – 15 times higher than other systems aimed at biologically producing methanol. However, the immobilization dramatically affected the methanol production ability of the cells. Methanol was shown to be produced by the immobilized cells with a maximum production activity of 0.12 ± 0.08 mmol/gVSS.hr. This activity was much lower than the typical reported value of 1.0 mmol/g dry weight.hr (Hyman and Wood 1983). The maximum methanol concentration achieved in this system was 0.129 ± 0.102 mM, significantly lower than previous reported values, ranging between 0.6 mM and 2 mM (Chapman, Gostomski, and Thiele 2004). The results also showed that the addition of methane had an effect on the energy gaining metabolism (ammonia oxidation) of the bacteria, reducing the ammonia oxidation capacity by up to 70%. It was concluded, because of the low methanol production activity and the low methanol concentrations produced, that this system was not suitable for a methanol biosynthesis process.
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37

Fratesi, Guido. "Low temperature methane-to-methanol conversion on transition metal surfaces. An ab initio study." Doctoral thesis, SISSA, 2005. http://hdl.handle.net/20.500.11767/4087.

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38

Nealon, Jeffrey W. "Dynamics of methane migration in marine hydrate systems examples from the Guaymas Transform, Blake Ridge, and Storegga landslide /." Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1188873751&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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39

Guan, Xiangguo. "The photochemistry of polyhalomethanes in water and the water-catalyzed dehalogenation reactions of selected isopolyhalomethanes, halogenated methanols and halogenated formaldehydes." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38718960.

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40

Guan, Xiangguo, and 官向國. "The photochemistry of polyhalomethanes in water and the water-catalyzed dehalogenation reactions of selected isopolyhalomethanes,halogenated methanols and halogenated formaldehydes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38718960.

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41

Riekie, Gail Jocelyn. "Can methane be oxidised anaerobically in soil?" Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59018.

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42

Jin, Qinghua. "GASMAK2 model for longwall gob gas emission." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2706.

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Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains x, 93 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 71-72).
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43

Bräunlich, Maya. "Study of atmospheric carbon monoxide and methane Untersuchung von atmosphärischen Kohlenmonoxid und Methan anhand von Isotopenmessungen /." [S.l. : s.n.], 2000. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB8832641.

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44

Graham, Andrew W. "Methane along the western Mexican margin." Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/6976.

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Methane and the processes controlling its distribution along the western Mexican margin were investigated in November 2001. Water column and sediment core samples were collected from 14 stations along the margin, in and around the Gulf of California, for shore-based analysis of methane concentrations and methane stable carbon isotopic ratios. These stations occupied both basin and open margin sites in and below the oxygen minimum zone. Methane concentrations in the upper 200 m of the water column were supersaturated at all sites. The sea-air fluxes of methane that resulted from this supersaturation ranged between 0.85 and 5.0 umol m-2 d-1, indicating that methane fluxes from this area are not significantly larger than from other ocean areas. Local subsurface methane maxima had concentrations ranging from 4.6 to 10.1 nM, larger than those found at open ocean stations (2 - 4 nM). Below 200 m, the hydrocast stations fell into 3 groups: silled basins, open margin sites with sediments below the oxygen minimum zone, and open margin sites with sediments intersecting the oxygen minimum zone. Both silled basin sites had highly elevated methane concentrations (24.9 - 48 nM) in the bottom waters overlying the sediments. The S13C values of this methane ranged from -54 to -59 vs. PDB. The majority of the open margin sites had seafloor depths which were positioned below the oxygen minimum zone (> 1000 m) and contained relatively low methane concentrations below the subsurface maximum. Two open margin stations with water depths (590 and 450 m) that intersect the oxygen minimum zone had highly elevated methane concentrations throughout the water column. A maximum methane concentration of 78 nM, associated with the isotopically depleted S13C value of - 60 , was found overlying the sediments at the southernmost station. Sediment pore water methane concentrations were low but increased dramatically once sulfate concentrations decreased to < 3 mM. The depth of the sulfate reduction zone was shallow (80 - 100 cm) at the stations on the west side of Baja California but deeper (> 150 cm) and variable inside the Gulf of California. Methane fluxes from the sediments ranged from 0.24 to 5.5 umol m-2 d-1, with the highest fluxes observed on the west side of Baja California. Stations with seafloors in the oxygen minimum zone had much higher methane concentrations throughout the water column than stations with seafloors below the oxygen minimum zone. The sediments along the western Mexican margin could be a source of methane to the eastern tropical North Pacific at locations where the margin and oxygen minimum zone intersect.
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45

Mpuhlu, Batsho. "Synthesis of P-Methane-3,8-Diol." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/570.

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The synthesis of para-menthane-3,8-diol in a batch reactor was investigated in some detail with the view to evaluate the potential of producing said p-menthane- 3,8-diol in a continuous-flow reactor from the results obtained from the batch process. The methodology used as base for this investigation was a published procedure by Takasago of Japan. The Takasago-method produced 92.3 percent Yield for the product para-menthane-3,8-diol, and 2.7 percent Yield of the by-product, acetal. The objective for this investigation was to produce a minimum p-menthane-3,8- diol content of 97.0 percent and a maximum content of 3.0 percent for the by-product acetal. The batch production process was evaluated in detail using statistical experimental design methodologies. Three process variables, namely catalyst loading, organic/aqueous phase ratio and reaction temperature were selected for the study. The experimental method was based on the Takasago procedure, however the substrate was added as a single slug as opposed to gradual addition method and the reaction period was reduced to 30 minutes. Apart from statistical analysis, mechanistic aspects were also used to interpret the following results. Using a central composite design, three response models (one for the conversion of citronellal, p-menthane-3,8-diol and acetal formation) were determined. An analysis of the response surfaces indicated that, to increase the citronellal conversion all three variables should be increased. To increase the amount of pmenthane- 3,8-diol, the reaction temperature and acid concentration should be increased, but the Aq/org ratio should be decreased as the acid catalyst concentration is increased. To minimize the amount of acetals formed during the reaction, the Aq/org ratio should be decreased; temperature and acid concentration can be decreased or increased. The reaction mechanism suggested that p-menthane-3,8-diol may be formed along two pathways: One pathway directly forms p-menthane-3,8-diol, whilst the second pathway forms the isopulegol first, then proceeds to form product by hydrolysis. The acetal is formed as result of the reaction between unreacted citronellal and p-menthane-3,8-diol. From the design experiments it was suggested that reaction time can be reduced to 8 minutes at reaction temperatures between, 80-85 0C The product and acetal were isolated by simple vacuum evaporation of the low boiling citronellal and isopulegol. Results from recycling the catalyst phase were similar to those of the initial process. The results of this investigation has clearly shown that with a proper understanding of the effect of process variables on the performance of the batch synthesis route, the conversion of this traditionally batch (actually semi-batch) process into a continuous process is quite feasible provided that suitable equipment is available. The most important features required for such equipment would be: Intense mixing throughout the reaction zone so as to maximise the surface area between the two immiscible phases, hence the rate of mass transfer between the two phases; and the ability to run reactions above the boiling point of water. Plans for the further study of the process are already well underway and sections of static mixing tubes have been acquired to build a continuous lab scale tubular reactor that would be capable of providing the level of mixing required.
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46

Brown, Ann. "Methane production in Canadian muskeg bogs." Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/21229.

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47

AlBanna, Muna. "Methane oxidation in landfill cover soil." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/26834.

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Methane, one of the primary greenhouse gases, negatively affects climate change. Its atmospheric concentration has increased dramatically over the last century and is expected to continue rising due to human activities. Oxidation of methane by methanotrophic bacteria provides a sink for methane. The rate at which methane is biologically oxidized depends on different parameters. This study aims to better understand methane oxidation in landfill cover soils. This was done through laboratory batch reactor experiments, under two levels of moisture content, two soil layer thicknesses and with and without nutrient additions. Adding nutrients to the 200 mm layer of landfill cover soil that contained 30% moisture content (by weight), increased the CH4 oxidation efficiency from 38% to 81% and the CH4 substrate utilization from 2750 mumoles/L to 5540 mumoles/L. The kinetic constants were studied in the landfill cover soil. The maximum CH4 utilization rate for different experimental runs and under different levels of the three specified parameters were between 31 and 699 mumoles/dayxkg of dry soil weight. A statistical design model was developed to describe the expected methane oxidation efficiencies under different levels of moisture content and nutrient addition that can occur in a typical landfill cover soil.
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48

Karimi, Kaveh Petroleum Engineering Faculty of Engineering UNSW. "Coal bed methane reservoir simulation studies." Awarded by:University of New South Wales. School of Petroleum Engineering, 2005. http://handle.unsw.edu.au/1959.4/22449.

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The purpose of this study is to perform simulation studies for a specific coal bed methane reservoir. First, the theory and reservoir engineering aspects of coal bed methane reservoirs, such as dual porosity concept, permeability characteristics of CBM reservoirs and mechanism of gas storage and gas transportation in CBM reservoir have been discussed. Next, simulation results for the CBM reservoir presented. Simulation studies were carried out by using the CBM reservoir simulator, SIMED II. Injection/fall-off test pressure data were interpreted based on the pressure history matching method. The interpretation results include the determination of reservoir permeability and identification of the reservoir altered zone. Also available production histories were used to simulate the reservoir production behavior. Then the production model was used to predict the reservoir future production and to carry out sensitivity analysis on reservoir performance. For natural pressure depletion, methane recovery was increased significantly as reservoir permeability was increased. Well-bore fracturing creates a fractured zone with higher permeability. This increases methane production rate during early time of reservoir life. Reservoir matrix porosity has a significant effect on the reservoir performance. Higher production peak rate and also higher methane recovery was obtained for the reservoir with lower porosity values. Any increase in the reservoir compressibility causes greater reduction in reservoir absolute permeability as well as relative permeability to gas throughout the reservoir. Therefore, methane recovery decreased as the reservoir compressibility increased. The reservoir production behavior was strongly affected by changes in reservoir size. The production peak rate was significantly postponed and lowered as reservoir size was increased. The effect of reservoir initial pressure was investigated and the results show that higher initial reservoir pressure leads to higher production rate during early years of production. However, for the later years of reservoir life, the production profile is almost identical for different initial pressures. Coal desorption time constant affects the methane production by its own scale. In this study, the range of desorption time did not exceed longer than three days and therefore the difference in production rate was observed only in the first few days of production.
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49

Dong, Yan. "Reducing methane emissions from ruminant animals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ34756.pdf.

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50

Konieczny, Agnieszka. "Hydrogen by thermocatalytic decomposition of methane /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1240703551&sid=4&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Thesis (M.S.)--Southern Illinois University Carbondale, 2006.
"Department of Mechanical Engineering and Energy Processes." Includes bibliographical references (leaves 76-80). Also available online.
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