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Methane Control Research: Summary of Results, 1964-80

Description: From Abstract: "This bulletin summarizes the work conducted under the Bureau of Mines methane control research program during the years 1964 to 1979. This bulletin provides a comprehensive source of information on the accomplishments of the Bureau's methane control research program, on the technology developed, and the direction of further research."
Date: unknown
Creator: Deul, Maurice & Kim, Ann G.
Partner: UNT Libraries Government Documents Department

Microbial ecology of thermophilic anaerobic digestion. Final report

Description: This grant supported research on methanogenic archaea. The two major areas that were supported were conversion of acetic acid to methane and nitrogen fixation by Methanosarcina. Among the achievements of this research were the isolation of novel methanogenic cultures, elucidation of the pathways from acetate to methane, description of a specific DNA-binding complex in nitrogen fixing methanogens, and demonstration of an alternative nitrogenase in Methanosarcina.
Date: April 15, 2000
Creator: Zinder, Stephen H.
Partner: UNT Libraries Government Documents Department

Growing carbon nanotubes by chemical vapor deposition technique.

Description: Carbon nanotubes were synthesized in the laboratory using chemical vapor deposition at different methane concentration. I found that a methane concentration of 4 sccm was ideal for well recognizable carbon nanotubes. A higher concentration led to fewer nanotube growth and silicon carbide structure. Coating the sample first with Fe(NO3)3 created a catalyst base on the substrate for the nanotube to adhere and grow on.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: May 2000
Creator: Rajan, Harihar V.
Partner: UNT Libraries

Manifold methods for methane combustion

Description: Objective is to develop a new method for studying realistic chemistry in turbulent methane combustion with NO{sub x} mechanism. The realistic chemistry is a simplification to a more detailed chemistry based on the manifold method; accuracy is determined by interaction between the transport process and the chemical reaction. In this new (tree) method, probability density function or partially stirred reactor calculations are performed. Compared with the reduced mechanism, manifold, and tabulation methods, the new method overcomes drawbacks of the reduced mechanism method and preserves the advantages of the manifold method. Accuracy is achieved by specifying the size of the cell.
Date: December 31, 1995
Creator: Yang, B. & Pope, S.B.
Partner: UNT Libraries Government Documents Department

Direct Aromaization of Methane

Description: The thermal decomposition of methane offers significant potential as a means of producing higher unsaturated and aromatic hydrocarbons when the extent of reaction is limited. Work in the literature previous to this project had shown that cooling the product and reacting gases as the reaction proceeds would significantly reduce or eliminate the formation of solid carbon or heavier (Clo+) materials. This project studied the effect and optimization of the quenching process as a means of increasing the amount of value added products during the pyrolysis of methane. A reactor was designed to rapidly quench the free-radical combustion reaction so as to maximize the yield of aromatics. The use of free-radical generators and catalysts were studied as a means of lowering the reaction temperature. A lower reaction temperature would have the benefits of more rapid quenching as well as a more feasible commercial process due to savings realized in energy and material of construction costs. It was the goal of the project to identify promising routes from methane to higher hydrocarbons based on the pyrolysis of methane.
Date: January 15, 1997
Creator: Marcelin, George
Partner: UNT Libraries Government Documents Department

Landfill Gas Conversion to LNG and LCO{sub 2}. Phase II Final Report for January 25, 1999 - April 30, 2000

Description: This report summarizes work on the development of a process to produce LNG (liquefied methane) for heavy vehicle use from landfill gas (LFG) using Acrion's CO{sub 2} wash process for contaminant removal and CO{sub 2} recovery.
Date: October 20, 2000
Creator: Brown, W. R.; Cook, W. J. & Siwajek, L. A.
Partner: UNT Libraries Government Documents Department

Effect of Carbon Dioxide on SAES(R) St909 Methane Cracking

Description: Methane/carbon dioxide cracking tests using a bench scale system have been performed using SAES(R) St909 getter. The report shows carbon dioxide reduced the St909 methane cracking efficiency under a variety of test conditions. These bench scale tests revealed the complex interactions between reactive species expected to be present in future plant operations.
Date: September 30, 2002
Creator: Klein, J.E.
Partner: UNT Libraries Government Documents Department

Soft Radiation From Pu²³⁹

Description: "The radiation from Pu²³⁹ have been studied in the region 5-25 keV. For this purpose, a proportional counter, filled with argon to a pressure of 53 cm Hg and with methane to a pressure of 6 cm Hg, was employed in combination with a single-channel pulse analyzer and associated amplifying and counting circuits."
Date: 1952
Creator: Israel, Harvey Ira
Partner: UNT Libraries Government Documents Department

Theoretical Rocket Performance of Liquid Methane with Several Fluorine-Oxygen Mixtures Assuming Frozen Composition

Description: "Theoretical rocket performance for frozen composition during expansion was calculated for liquid methane with several fluorine-oxygen mixtures for a range of pressure ratios and oxidant-fuel ratios. The parameters included are specific impulse, combustion-chamber temperature, nozzle-exit temperature molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, isentropic exponent, viscosity, and thermal conductivity. The maximum calculated value of specific impulse for a chamber pressure of 600 pounds per square inch absolute (40.827atm) and an exit pressure of 1 atmosphere is 315.3 for 79.67 percent fluorine in the oxidant" (p. 1).
Date: May 20, 1958
Creator: Gordon, Sanford & Kastner, Michael E.
Partner: UNT Libraries Government Documents Department

The Mechanisms of Methane C–H Activation and Oxy-insertion Via Small Transition Metal Complexes: a DFT Computational Investigation

Description: 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.
Date: May 2014
Creator: Prince, Bruce M.
Partner: UNT Libraries

Computational Study of Small Molecule Activation via Low-Coordinate Late First-Row Transition Metal Complexes

Description: Methane and dinitrogen are abundant precursors to numerous valuable chemicals such as methanol and ammonia, respectively. However, given the robustness of these substrates, catalytically circumventing the high temperatures and pressures required for such transformations has been a challenging task for chemists. In this work, computational studies of various transition metal catalysts for methane C-H activation and N2 activation have been carried out. For methane C-H activation, catalysts of the form LnM=E are studied, where Ln is the supporting ligand (dihydrophosphinoethane or β-diketiminate), E the activating ligand (O, NCH3, NCF3) at which C-H activation takes place, and M the late transition metal (Fe,Co,Ni,Cu). A hydrogen atom abstraction (HAA) / radical rebound (RR) mechanism is assumed for methane functionalization (CH4 à CH3EH). Since the best energetics are found for (β-diket)Ni=O and (β-diket)Cu=O catalysts, with or without CF3 substituents around the supporting ligand periphery, complete methane-to-methanol cycles were studied for such systems, for which N2O was used as oxygen atom transfer (OAT) reagent. Both monometallic and bimetallic OAT pathways are addressed. Monometallic Fe-N2 complexes of various supporting ligands (LnFe-N2) are studied at the beginning of the N2 activation chapter, where the effect of ligand on N2 activation in end-on vs. side-on N2 isomers is discussed. For (β-diket)Fe-N2 complexes, the additional influence of diketiminate donor atom (N(H) vs. S) is briefly addressed. The remainder of the chapter expands upon the treatment of β-diketiminate complexes. First, the activation and relative stabilities of side-bound and end-bound N2 isomers in monometallic ((β-diket)M-N2) and bimetallic ((β-diket)M-N2-M(β-diket)) first row transition metal complexes are addressed. Second, the thermodynamics of H/H+/H- addition to (β-diket)Fe-bound N2, followed by subsequent H additions up to release of ammonia, is discussed, for which two mechanisms (distal and alternating) are considered. Finally, the chapter concludes with partial distal and alternating mechanisms for H addition to N2 ...
Date: May 2010
Creator: Pierpont, Aaron
Partner: UNT Libraries

An experimental and density functional theory study of the interactions of CH4 with H-ZSM-5

Description: The interactions of methane with Bronsted acid sites in H-ZSM-5 were investigated both experimentally and theoretically. Diffuse reflectance infrared spectroscopy was used to acquire spectra for methane adsorbed on H-ZSM-5 at room temperature and at 77 K. Upon adsorption, the v1 and v3 vibrational bands of methane shift by -15 and -23 cm-1, respectively, and the vibrational band for OH groups associated with Bronsted acid sites shifts by -93 cm-1. Quantum chemical calculations conducted at the DFT level of theory with a 6-31g**++ basis set show that the observed shifts for methane are attributable to the effects of the electrostatic field created by the atoms of the zeolite. To represent the influence of the zeolite on the adsorbed methane correctly, it is essential to take into account the effects of the Madelung field, as well as the local effects of the acid center. The calculated shift in the vibrational frequency of the bridging OH group lies within the range observed experimentally. However, the quantitative agreement of the calculated and observed shift is not as good as that seen for the bands of CH4.
Date: August 25, 2001
Creator: Khaliullin, Rustam Z.; Bell, Alexis T. & Kazansky, Vladimir B.
Partner: UNT Libraries Government Documents Department

Final Report

Description: The aim of this project was to determine phase equilibrium and PVT properties of fluids in the water-methane system using synthetic fluid inclusions. This information is critical to understanding the behavior of natural fluid inclusions trapped in hydrocarbon-bearing environments such as sedimentary basins, oil and gas fields, methane hydrate occurrences and Mississippi Valley type Pb-Zn deposits.
Date: June 15, 2005
Creator: Bodnar, R. J.
Partner: UNT Libraries Government Documents Department

Hydrogen Safety Issues Compared to Safety Issues with Methane andPropane

Description: The hydrogen economy is not possible if the safety standards currently applied to liquid hydrogen and hydrogen gas by many laboratories are applied to devices that use either liquid or gaseous hydrogen. Methane and propane are commonly used by ordinary people without the special training. This report asks, 'How is hydrogen different from flammable gasses that are commonly being used all over the world?' This report compares the properties of hydrogen, methane and propane and how these properties may relate to safety when they are used in both the liquid and gaseous state. Through such an analysis, sensible safety standards for the large-scale (or even small-scale) use of liquid and gaseous hydrogen systems can be developed. This paper is meant to promote discussion of issues related to hydrogen safety so that engineers designing equipment can factor sensible safety standards into their designs.
Date: August 20, 2005
Creator: Green, Michael A.
Partner: UNT Libraries Government Documents Department

Primordial Organic Chemistry. I. Compounds Resulting from Electron Irradiation of C<sup>14</sup>H<sub>4</sub>

Description: C{sup 14}-labeled methane, together with a number of other presumed primordial gases of the earth's atmosphere, has been subjected to electron bombardments. The products formed have been examined by paper chromatography, ion exchange chromatography, mass spectrometry, and ultraviolet light spectrophotometry. A number of minor molecules have been specifically identified, and urea has been found as a major component in the absence of added phosphine; the formation of urea is inhibited by added phosphine. Most of the products can be accounted for as discrete molecules, even though they are as yet unidentified.
Date: December 1, 1961
Creator: Palm, Christopher & Calvin, Melvin
Partner: UNT Libraries Government Documents Department