Author: Michael O'Neal NuttPublisher:
ISBN:
Category :
Languages : en
Pages : 142
Book Description
Non-oxidative Coupling of Methane for Use in a Hydrogen Transporting Membrane Reactor
Author: Michael O'Neal NuttNon-oxidative Methane Conversion on Mo/H-ZSM5 Catalysts for Use in a Hydrogen-transport Membrane Reactor
Author: Borry Richard WilsonPublisher:
ISBN:
Category :
Languages : en
Pages : 310
Book Description
Non-oxidative Conversion of Methane with Continuous Hydorgen Removal
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
The objective is to overcome the restrictions of non-oxidative methane pyrolysis and oxidative coupling of methane by transferring hydrogen across a selective inorganic membrane between methane and air streams, without simultaneous transport of hydrocarbon reactants or products. This will make the overall reaction system exothermic, remove the thermodynamic barrier to high conversion, and eliminate the formation of carbon oxides. Our approach is to couple C-H bond activation and hydrogen removal by passage of hydrogen atoms through a dense ceramic membrane. In our membrane reactor, catalytic methane pyrolysis produces C2+ hydrogen carbons and aromatics on the one side of the membrane and hydrogen is removed through an oxide film and combusted with air on the opposite side. This process leads to a net reaction with the stoichiometry and thermodynamic properties of oxidative coupling, but without contact between the carbon atoms and oxygen species.
Non-porous Hydrogen-selective Inorganic Membranes for Methane Conversion to Higher Hydrocarbons
Author: Eric Chen LuCatalysis
Author: James SpiveyPublisher: Royal Society of Chemistry
ISBN: 1788014545
Category : Catalysis
Languages : en
Pages : 376
Book Description
Catalysts are required for a variety of applications and researchers are increasingly challenged to find cost effective and environmentally benign catalysts to use. This volume looks at modern approaches to catalysis and reviews the extensive literature including direct methane conversion, nanocomposite catalysts for transformation of biofuels into syngas and hydrogen, and catalytic wet air oxidation technology for industrial wastewater treatment. Appealing broadly to researchers in academia and industry, it will be of great benefit to any researcher wanting a succinct reference on developments in this area now and looking to the future.
OXIDATIVE COUPLING OF METHANE USING INORGANIC MEMBRANE REACTORS.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 365
Book Description
The objective of this research is to study the oxidative coupling of methane in catalytic inorganic membrane reactors. A specific target is to achieve conversion of methane to C2 hydrocarbons at very high selectivity and higher yields than in conventional non-porous, co-feed, fixed bed reactors by controlling the oxygen supply through the membrane. A membrane reactor has the advantage of precisely controlling the rate of delivery of oxygen to the catalyst. This facility permits balancing the rate of oxidation and reduction of the catalyst. In addition, membrane reactors minimize the concentration of gas phase oxygen thus reducing non selective gas phase reactions, which are believed to be a main route for the formation of CO(subscript x) products. Such gas phase reactions are a cause of decreased selectivity in the oxidative coupling of methane in conventional flow reactors. Membrane reactors could also produce higher product yields by providing better distribution of the reactant gases over the catalyst than the conventional plug flow reactors. Membrane reactor technology also offers the potential for modifying the membranes both to improve catalytic properties as well as to regulate the rate of the permeation/diffusion of reactants through the membrane to minimize by-product generation. Other benefits also exist with membrane reactors, such as the mitigation of thermal hot-spots for highly exothermic reactions such as the oxidative coupling of methane. The application of catalytically active inorganic membranes has potential for drastically increasing the yield of reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity.
Integrated Catalytic Membrane Reactor for Oxidative Coupling of Methane
Author: Michiel BoeckxMethane Coupling by Membrane Reactor. Quarterly Report, June 25--September 24, 1996
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
To prevent the deep oxidation of methane catalyzed by the direct contact between methane and the dense membrane material (SrFeCo{sub 0.5}O{sub 3-x}), BaCe{sub 0.6}Sm{sub 0.4}O3 perovskite was coated on the inner surface of the dense membrane tube by the sol-gel technique. Different pretreatment methods were tested to compare their effects on the coated film. The morphology of the coated membrane was studied by SEM. The BaCe{sub 0.6}Sm{sub 0.4}O3-coated membrane which was pretreated with a basic solution before coating was more evenly covered by the coating material. The oxygen permanence through the modified membrane tube were measured at different temperatures. The oxygen permanence were found to be about 70% lower than those of the unmodified tubes. The catalytic runs were carried out with La/MgO catalyst packed inside the membrane tube. The C2 yields obtained using the dense membrane reactor were less than 4%. This may have resulted from the fact that the methane fed to the tube side was still exposed to the uncoated area of the dense membrane surface due to the incomplete coverage of the coating material (BaCe{sub 0.6}Sm{sub 0.4}O3). A hybrid dense membrane reactor, in which the oxygen was supplied by co-feeding oxygen with methane to the tube side and feeding air to the shell side, was used for the oxidative coupling of methane. Again, the inner surface of the membrane tube was coated with BaCe{sub 0.6}Sm{sub 0.4}O3 by the sol-gel technique, and the La/MgO catalyst was packed inside the membrane tube. The oxygen permanence through the membrane tube was found to be about ten times higher than that under non-reaction conditions. C2 yields up to 12% were obtained using the coated dense membrane reactor. These yields are higher than those obtained in an uncoated dense membrane reactor setup with methane and oxygen co-fed into the tube side, where the same catalyst was packed.
Steady-state and Transient Catalytic Oxidation and Coupling of Methane
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
This project addresses the conversion of methane from natural gas into ethane, ethylene and higher hydrocarbons. Our research explores the mechanistic and practical implications of carrying out the methane oxidative coupling reaction in reactor designs other than conventional packed-beds with co-fed reactants. These alternate reactor designs are needed to prevent the full oxidation of methane, which limits C2, yields in methane oxidative coupling reactions. The research strategy focuses on preventing contact between the 02 reactant required for favorable overall thermodynamics and the C{sub 2+} products of methane coupling. The behavior of various reactor designs are simulated using detailed kinetic transport models. These simulations have suggested that the best way to prevent high C02 yields is to separate the oxygen and hydrocarbon streams altogether. As a result, the project has focused on the experimental demonstration of proton transport membrane reactors for the selective conversion of methane into higher hydrocarbons.
Author: S. Bhatia