Download or read book Catalytic Conversion of Methane to Partially Oxidized Products Over Copper exchanged Zeolites written by Kimberly Tam Dinh and published by . This book was released on 2020 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: The selective conversion of methane to liquid oxygenated compounds is a grand challenge in catalysis. Although natural gas can be processed industrially in large-scale facilities, new catalytic processes are required that economically directly convert methane to liquid products in small-scale units to exploit highly abundant but difficult-to-access gas reserves. Our group recently reported the first instance of a continuous, gas phase catalytic process for the direct conversion of methane to methanol using copper-exchanged zeolites by feeding only methane, water, and oxygen at 473 K. While this continuous system is an attractive route for the mild conversion of methane to value-added products, fundamental understanding of the reaction pathway and active site is necessary to engineer improved catalysts and an improved process. Thus, my thesis has investigated the fundamental kinetics and active site requirements for continuous partial methane oxidation and using this knowledge to design an improved process. First, a reaction pathway and a [Cu-O-Cu]2+ motif as the active site were identified for the selective catalytic conversion of methane to methanol. Kinetic analysis on copper-exchanged SSZ-13 zeolites across a range of Cu loadings and Al spatial distributions revealed the reaction pathway is initiated by rate-limiting C-H bond scission of methane. Water is kinetically inconsequential, but required for methanol desorption. Carbon dioxide is generated from the sequential over oxidation of partially oxidized intermediates and downstream methanol oxidation. Selective partial oxidation was achieved with catalyst samples of high Al content and moderate Cu content (Cu/cage

Download or read book Methane Conversion by Oxidative Processes written by Wolf and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reasonable case could be made that the scientific interest in catalytic oxidation was the basis for the recognition of the phenomenon of catalysis. Davy, in his attempt in 1817 to understand the science associated with the safety lamp he had invented a few years earlier, undertook a series of studies that led him to make the observation that a jet of gas, primarily methane, would cause a platinum wire to continue to glow even though the flame was extinguished and there was no visible flame. Dobereiner reported in 1823 the results of a similar investigation and observed that spongy platina would cause the ignition of a stream of hydrogen in air. Based on this observation Dobereiner invented the first lighter. His lighter employed hydrogen (generated from zinc and sulfuric acid) which passed over finely divided platinum and which ignited the gas. Thousands of these lighters were used over a number of years. Dobereiner refused to file a patent for his lighter, commenting that "I love science more than money." Davy thought the action of platinum was the result of heat while Dobereiner believed the ~ffect ~as a manifestation of electricity. Faraday became interested in the subject and published a paper on it in 1834; he concluded that the cause for this reaction was similar to other reactions.

Download or read book Methane Oxidation Over Dual Redox Catalysts written by and published by . This book was released on 1992 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C[sub 2] hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C[sub 2] hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe[sup III] or Sn[sup IV], was found to be essential for the selectivity switch from C[sub 2] coupling products to formaldehyde. The principle of double doping with an oxygen activator (Cu) and the redox Lewis acid (Fe, Sn) was pursued further by synthesizing and testing the CuFe-ZSM-5 zeolite catalyst. The Cu[sup II](ion exchanged) Fe[sup III](framework)-ZSM-5 also displayed activity for formaldehyde synthesis, with space time yields exceeding 100 g/h-kg catalyst. However, the selectivity was low and earlier claims in the literature of selective oxidation of methane to methanol over CuFe-ZSM-5 were not reproduced. A new active and selective catalytic system (M=Sb, Bi, Sn)/SrO/La[sub 2]O[sub 3] has been discovered for potentially commercially attractive process for the conversion of methane to C[sub 2] hydrocarbons, (ii) a new principle has been demonstrated for selectivity switching from C[sub 2] hydrocarbon products to formaldehyde in methane oxidations over Cu, Fe-doped zinc oxide and ZSM-5, and (iii) a new approach has been initiated for using ultrafine metal dispersions for low temperature activation of methane for selective conversions. Item (iii) continues being supported by AMOCO while further developments related to items (i) and (ii) are the objective of our continued effort under the METC-AMOCO proposed joint program.

Download or read book Methane Oxidation Over Dual Redox Catalysts Final Report written by and published by . This book was released on 1992 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C2 hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C2 hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe{sup III} or Sn{sup IV}, was found to be essential for the selectivity switch from C2 coupling products to formaldehyde. The principle of double doping with an oxygen activator (Cu) and the redox Lewis acid (Fe, Sn) was pursued further by synthesizing and testing the CuFe-ZSM-5 zeolite catalyst. The Cu{sup II}(ion exchanged) Fe{sup III}(framework)-ZSM-5 also displayed activity for formaldehyde synthesis, with space time yields exceeding 100 g/h-kg catalyst. However, the selectivity was low and earlier claims in the literature of selective oxidation of methane to methanol over CuFe-ZSM-5 were not reproduced. A new active and selective catalytic system (M=Sb, Bi, Sn)/SrO/La2O3 has been discovered for potentially commercially attractive process for the conversion of methane to C2 hydrocarbons, (ii) a new principle has been demonstrated for selectivity switching from C2 hydrocarbon products to formaldehyde in methane oxidations over Cu, Fe-doped zinc oxide and ZSM-5, and (iii) a new approach has been initiated for using ultrafine metal dispersions for low temperature activation of methane for selective conversions. Item (iii) continues being supported by AMOCO while further developments related to items (i) and (ii) are the objective of our continued effort under the METC-AMOCO proposed joint program.

Download or read book Theoretical Insights Into the Selective Oxidation of Methane to Methanol in Copper exchanged Mordenite written by and published by . This book was released on 2016 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selective oxidation of methane to methanol is one of the most difficult chemical processes to perform. A potential group of catalysts to achieve CH4 partial oxidation are Cu-exchanged zeolites mimicking the active structure of the enzyme methane monooxygenase. However, the details of this conversion, including the structure of the active site, are still under debate. In this contribution, periodic density functional theory (DFT) methods were employed to explore the molecular features of the selective oxidation of methane to methanol catalyzed by Cu-exchanged mordenite (Cu-MOR). We focused on two types of previously suggested active species, CuOCu and CuOOCu. Our calculations indicate that the formation of CuOCu is more feasible than that of CuOOCu. In addition, a much lower C-H dissociation barrier is located on the former active site, indicating that C-H bond activation is easily achieved with CuOCu. We calculated the energy barriers of all elementary steps for the entire process, including catalyst activation, CH4 activation, and CH3OH desorption. Finally, our calculations are in agreement with experimental observations and present the first theoretical study examining the entire process of selective oxidation of methane to methanol.

Download or read book Methane Conversion by Oxidative Processes written by Eduardo E. Wolf and published by Springer. This book was released on 1992 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reasonable case could be made that the scientific interest in catalytic oxidation was the basis for the recognition of the phenomenon of catalysis. Davy, in his attempt in 1817 to understand the science associated with the safety lamp he had invented a few years earlier, undertook a series of studies that led him to make the observation that a jet of gas, primarily methane, would cause a platinum wire to continue to glow even though the flame was extinguished and there was no visible flame. Dobereiner reported in 1823 the results of a similar investigation and observed that spongy platina would cause the ignition of a stream of hydrogen in air. Based on this observation Dobereiner invented the first lighter. His lighter employed hydrogen (generated from zinc and sulfuric acid) which passed over finely divided platinum and which ignited the gas. Thousands of these lighters were used over a number of years. Dobereiner refused to file a patent for his lighter, commenting that "I love science more than money." Davy thought the action of platinum was the result of heat while Dobereiner believed the ~ffect ~as a manifestation of electricity. Faraday became interested in the subject and published a paper on it in 1834; he concluded that the cause for this reaction was similar to other reactions.

Download or read book The Catalytic Conversion of Methane by Partial Oxidation written by Woodhouse Jeremy Robert and published by . This book was released on 1989 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Methane Partial Oxidation Over Phthalocyanine Catalyst written by Yuan Zhu and published by . This book was released on 2013 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: The partial oxidation reaction of methane over a zeolite-supported ruthenium phthalocyanine catalyst is studied in a packed bed reactor. The investigation of such reaction is desirable because partial oxidation of methane yields a synthesis gas that can be upgraded to liquid chemicals and fuels. Reactants of this study are He-diluted CH4 and O2. The effluent includes unreacted CH4 and O2, He, CO, CO2, H2, and H2O vapor. Thermal conductivity gas chromatography is applied to identify the mole fractions of reactants and products. System pressure is maintained at 50 psig. Experiments are run at 250, 275, 300, 325, 350, and 375°C. For each temperature, the feed molar ratio of CH4/O2 is varied from 0.5 to 5.0. Although reaction temperature is more than 200°C lower than that of common catalytic methane partial oxidation, conversion of methane is obvious. Product analysis indicates that the highest conversion is 80.4% at 375°C, CH4/O2=0.5. Conversion of methane increases with increasing temperature, but it decreases with increasing molar ratio CH4/O2. Selectivities of both H2 and CO increase with the increasing temperature or molar ratio CH4/O2. But selectivity of CO2 decreases with the increasing temperature or molar ratio CH4/O2. Based on a differential packed bed reactor model, the global rate of CH4 reaction shows first order dependencies on each of O2 and CH4. The overall reaction rate is a second-order reaction. The reaction rate constant k for each temperature was also determined. An Arrhenius plot of the global rate constants suggest that the reaction is limited by reaction kinetics between 250-300°C, and limited by mass transfer between 300-375°C. Equilibrium calculations are also made for all cases in this study. The result shows that products selectivities of equilibrium calculation are significantly different from that of catalytic reactions, which emphasizes the effective catalytic actions of the zeolite-supported ruthenium phthalocyanine.

Download or read book Methane Conversion written by D.M. Bibby and published by Elsevier. This book was released on 1988-03-01 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume comprises the invited plenary lectures, contributed and poster papers presented at a symposium organised to mark the successful inauguration of the world's first commercial plant for production of gasoline from natural gas, based on the Mobil methanol-to-gasoline process. The objectives of the Symposium were to present both fundamental research and engineering aspects of the development and commercialization of gas-to-gasoline processes. These include steam reforming, methanol synthesis and methanol-to-gasoline. Possible alternative processes e.g. MOGD, Fischer-Tropsch synthesis of hydrocarbons, and the direct conversion of methane to higher hydrocarbons were also considered.The papers in this volume provide a valuable and extremely wide-ranging overview of current research into the various options for natural gas conversion, giving a detailed description of the gas-to-gasoline process and plant. Together, they represent a unique combination of fundamental surface chemistry catalyst characterization, reaction chemistry and engineering scale-up and commercialization.

Download or read book Plasma Catalysis written by Annemie Bogaerts and published by MDPI. This book was released on 2019-04-02 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma catalysis is gaining increasing interest for various gas conversion applications, such as CO2 conversion into value-added chemicals and fuels, N2 fixation for the synthesis of NH3 or NOx, methane conversion into higher hydrocarbons or oxygenates. It is also widely used for air pollution control (e.g., VOC remediation). Plasma catalysis allows thermodynamically difficult reactions to proceed at ambient pressure and temperature, due to activation of the gas molecules by energetic electrons created in the plasma. However, plasma is very reactive but not selective, and thus a catalyst is needed to improve the selectivity. In spite of the growing interest in plasma catalysis, the underlying mechanisms of the (possible) synergy between plasma and catalyst are not yet fully understood. Indeed, plasma catalysis is quite complicated, as the plasma will affect the catalyst and vice versa. Moreover, due to the reactive plasma environment, the most suitable catalysts will probably be different from thermal catalysts. More research is needed to better understand the plasma–catalyst interactions, in order to further improve the applications.

Download or read book Natural Gas Conversion written by A. Holmen and published by Elsevier. This book was released on 1991-05-27 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings reflect the extensive fundamental and applied research efforts that are currently being made on the conversion of gas, in particular on the direct conversion of methane. The Symposium in Oslo focused on the following topics: Direct conversion of methane, Fischer-Tropsch chemistry, methanol conversion and natural gas conversion processes. The main aim was to present the state-of-the-art and progress currently being made within each of these areas. The book contains the papers presented and includes plenary lectures, short communications and posters. The papers will be of interest to scientists and engineers working in the field of gas conversion, transportation fuels, primary petrochemicals and catalysis.

Download or read book Catalysis and the Mechanism of Methane Conversion to Chemicals written by Toshihide Baba and published by Springer Nature. This book was released on 2020-04-18 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces various types of reactions to produce chemicals by the direct conversion of methane from the point of view of mechanistic and functional aspects. The chemicals produced from methane are aliphatic and aromatic hydrocarbons such as propylene and benzene, and methanol. These chemicals are created by using homogeneous catalysts, heterogeneous catalysts such as zeolites, and biocatalysts such as enzymes. Various examples of methane conversion reactions that are discussed have been chosen to illustrate how heterogeneous and homogenous catalysts and biocatalysts and/or their reaction environments control the formation of highly energetic species from methane contributing to C-C and C-O bond formation.

Download or read book Concepts of Modern Catalysis and Kinetics written by I. Chorkendorff and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until now, the literature has offered a rather limited approach to the use of fundamental kinetics and their application to catalytic reactions. Subsequently, this book spans the full range from fundamentals of kinetics and heterogeneous catalysis via modern experimental and theoretical results of model studies to their equivalent large-scale industrial production processes. The result is key knowledge for students at technical universities and professionals already working in industry. '... such an enterprise will be of great value to the community, to professionals as well as graduate and undergraduate students attempting to move into the field of modern catalysis and kinetics. I strongly recommend you publish this book based on the proposal.' - Prof. Dr. G. A. Samorjai, University of California 'Both authors are well respected specialists, with a very long record of original top-quality work and an international reputation. A book from these authors will be considered an authoritative piece of work, I definitely support this project and I am looking forward to use the book when published.' - Prof. Dr. D. E. Resasco, University of Oklahoma 'I wholly support the proposed project. The authors are very competent young colleagues and there is a real need for such a textbook' - Prof. Dr. G. Ertl, Fritz-Haber-Institut, Max-Planck-Gesellschaft, Berlin

Download or read book Metal Oxides in Heterogeneous Catalysis written by Jacques C. Vedrine and published by Elsevier. This book was released on 2018-01-11 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxides in Heterogeneous Catalysis is an overview of the past, present and future of heterogeneous catalysis using metal oxides catalysts. The book presents the historical, theoretical, and practical aspects of metal oxide-based heterogeneous catalysis. Metal Oxides in Heterogeneous Catalysis deals with fundamental information on heterogeneous catalysis, including reaction mechanisms and kinetics approaches.There is also a focus on the classification of metal oxides used as catalysts, preparation methods and touches on zeolites, mesoporous materials and Metal-organic frameworks (MOFs) in catalysis. It will touch on acid or base-type reactions, selective (partial) and total oxidation reactions, and enzymatic type reactions The book also touches heavily on the biomass applications of metal oxide catalysts and environmentally related/depollution reactions such as COVs elimination, DeNOx, and DeSOx. Finally, the book also deals with future trends and prospects in metal oxide-based heterogeneous catalysis. Presents case studies in each chapter that provide a focus on the industrial applications Includes fundamentals, key theories and practical applications of metal oxide-based heterogeneous catalysis in one comprehensive resource Edited, and contributed, by leading experts who provide perspectives on synthesis, characterization and applications

Download or read book Spatially Resolved Species and Temperature Profiles in the Catalytic Partial Oxidation of Methane and Ethane written by Nick Joseph Degenstein and published by . This book was released on 2007 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Activation of Dioxygen and Homogeneous Catalytic Oxidation written by D.H.R. Barton and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph consists of the proceedings of the Fifth International Symposium on the Activation of Dioxygen and Homogeneous Catalytic Oxidation, held in College Station, Texas, March 14-19, 1993. It contains an introductory chapter authored by Professors D. H. R. Barton and D. T. Sawyer, and twenty-nine chapters describing presentations by the plenary lecturers and invited speakers. One of the invited speakers, who could not submit a manuscript for reasons beyond his control, is represented by an abstract of his lecture. Also included are abstracts of forty-seven posters contributed by participants in the symposium. Readers who may wish to know more about the subjects presented in abstract form are invited to communicate directly with the authors of the abstracts. This is the fifth international symposium that has been held on this subject. The first was hosted by the CNRS, May 21-29, 1979, in Bendor, France (on the Island of Bandol). The second meeting was organized as a NATO workshop in Padova, Italy, June 24-27, 1984. This was followed by a meeting in Tsukuba, Japan, July 12-16, 1987. The fourth symposium was held at Balatonfured, Hungary, September 10-14, 1990. The sixth meeting is scheduled to take place in Delft, The Netherlands (late Spring, 1996); the organizer and host will be Professor R. A. Sheldon.

Download or read book Catalytic Reaction Synthesis for the Partial Oxidation of Methane to Formaldehyde written by Maria-Guadalupe Cardenas-Galindo and published by . This book was released on 1993 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: