Direct Catalytic Conversion of Methane to Higher Hydrocarbons Via Oxidative Coupling Over Perovskite-type Oxides

Direct Catalytic Conversion of Methane to Higher Hydrocarbons Via Oxidative Coupling Over Perovskite-type Oxides PDF Author: Wolfgang J. Garcia Barre
Publisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 554

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Direct Catalytic Conversion of Methane to Higher Hydrocarbons Via Oxidative Coupling Over Perovskite-type Oxides

Direct Catalytic Conversion of Methane to Higher Hydrocarbons Via Oxidative Coupling Over Perovskite-type Oxides PDF Author: Wolfgang J. Garcia Barre
Publisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 554

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Mechanism-Imposed Limitations on the Yield of Higher Hydrocarbons from the Oxidative Coupling of Methane, and Alternate Approaches to Methane Conversion

Mechanism-Imposed Limitations on the Yield of Higher Hydrocarbons from the Oxidative Coupling of Methane, and Alternate Approaches to Methane Conversion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12

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The conversion of methane to higher hydrocarbons via oxidative coupling over metal oxide catalysts is the subject of intense study as a route for natural gas upgrading. Detailed study on the reaction of methane over a mixed manganese-magnesium oxide implicates a mechanism involving generation of methyl radicals at the surface, followed by radical coupling as well as other radical reactions in the gas phase as the predominant mode of carbon-carbon bond formation. Analysis of the consequences of this mechanisms suggests that there is an inherent limit on yield, including a major adverse pressure effect, that may severely impact the potential utility of this route. Among several possible approaches to circumventing this limitation, a novel class of catalyst - transition metal-exchanged P -alumina -- has been found to be highly active for complete oxidation of methane. Results of catalytic and characterization studies will be presented.

Natural Gas Conversion V

Natural Gas Conversion V PDF Author: A. Parmaliana
Publisher: Elsevier
ISBN: 0080537308
Category : Technology & Engineering
Languages : en
Pages : 1005

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Book Description
On January 1988, the ascertained and economically accessible reserves of Natural Gas (NG) amounted to over 144,000 billion cubic meters worldwide, corresponding to 124 billion tons of oil equivalents (comparable with the liquid oil reserves, which are estimated to be 138 billion TOE). It is hypothesized that the volume of NG reserve will continue to grow at the same rate of the last decade. Forecasts on production indicate a potential increase from about 2,000 billion cubic meters in 1990 to not more than 3,300 billion cubic meters in 2010, even in a high economic development scenario. NG consumption represents only one half of oil: 1.9 billion TOE/y as compared to 3.5 of oil. Consequently, in the future gas will exceed oil as a carbon atom source. In the future the potential for getting energetic vectors or petrochemicals from NG will continue to grow.The topics covered in Natural Gas Conversion V reflect the large global R&D effort to look for new and economic ways of NG exploitation. These range from the direct conversion of methane and light paraffins to the indirect conversion through synthesis gas to fuels and chemicals. Particularly underlined and visible are the technologies already commercially viable.These proceedings prove that mature and technologically feasible processes for natural gas conversion are already available and that new and improved catalytic approaches are currently developing, the validity and feasibility of which will soon be documented. This is an exciting area of modern catalysis, which will certainly open novel and rewarding perspectives for the chemical, energy and petrochemical industries.

Natural Gas Conversion

Natural Gas Conversion PDF Author: A. Holmen
Publisher: Elsevier
ISBN: 0080879179
Category : Science
Languages : en
Pages : 585

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Book Description
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.

Catalytic Conversion of Carbon Monoxide and Methane Over Metal and Metal Oxide Catalysts

Catalytic Conversion of Carbon Monoxide and Methane Over Metal and Metal Oxide Catalysts PDF Author: Wenchi Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 93

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Book Description
Catalysis is of vital importance in a wide range of areas including energy processing and chemical production. Catalytic conversion of C1 sources such as carbon monoxide and methane to make hydrocarbon fuels and oxygenated products has far reaching implications especially in the context of the gradual depletion of crude oil resource and the potential surge in the natural gas production in the coming decades. The control over reaction activity and selectivity for the conversion CO and CH4 in the Fischer–Tropsch synthesis and oxidative coupling of methane (OCM) have received tremendous attention and have been proved challenging. This dissertation focuses on the catalytic conversion of CO (Fischer–Tropsch synthesis) using supported cobalt based bimetallic nanoparticle model catalysts and the oxidative coupling of methane with noble metal promoted metal oxide catalysts. Using colloidal synthesis, a series of cobalt based bimetallic nanoparticles Co–M (M = Mn, Ru, Rh, and Re) with well-defined sizes, shapes, and compositions were obtained. Detailed synthesis procedures were presented and key synthetic parameters were discussed. The as-synthesized nanoparticles were subjected to extensive in-situ X-ray spectroscopy studies using ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and X-ray absorption spectroscopy (XAS) under catalytic relevant conditions. Composition wise, the results indicate the surface concentration of Co on the as-synthesized Co–M bimetallic particles is slightly less than the bulk atomic Co %. While oxidation treatment led to a slight increase of the surface Co, major effect was seen after the reduction treatment where surface segregation of the second metal resulted in a drastic decrease of the surface Co content. The effect is more pronounced at elevated reduction temperatures. Under reaction conditions, the surface compositions remained similar to those after the reduction treatment at high temperatures. Among the bimetallics tested, the Co–Mn system is relatively less susceptible to surface reconstructions induced by oxidation and reduction treatments. In addition, the reducibility of Co was also shown to be modified depending on the second metal present and Re was proved to be most efficient in leading to a facile reduction of Co. Catalytic performance of the bimetallic catalysts supported on mesoporous silica MCF–17 indicates a positive effect in the catalytic activity for Co–Rh and Co–Mn systems, while Co–Re and Co–Cu showed decreased activity. Less pronounced promotion effect of the second metal on the product distribution was observed with only a slight increase in the selectivity towards C5+ products. The selectivities for CH4 and C5+ of the various Co–M bimetallic catalysts generally resemble those of pure Co catalysts. Although in extremely low selectivity, alcohols were also formed with Co–Rh and Co–Cu bimetallic catalysts. The appearance of longer chain alcohol such as propanol, which was not present for pure Co catalysts, is an evidence for potential synergistic promotion. For oxidative coupling of methane (OCM), the promotion effect of noble metals (Pt, Ir, and Rh) on the performance of MnxOy-Na2WO4/MCF–17 catalysts was investigated. The introduction of noble metals had little effect on the surface area and phase composition of the original catalyst but led to a more reduced nature of the surface oxide species. Catalytic study revealed an enhanced selectivity towards both C2 and C3 hydrocarbons as compared to the undoped MnxOy-Na2WO4/MCF–17 catalyst in the order of Rh-doped > Ir-doped > Pt-doped samples together with a lower olefin to paraffin ratio. A more optimized strength of interaction between the carbon intermediates and the catalyst surface was suggested, which in combination with the improved reducibility of Mn and W species are believed to be responsible for the improved performance. In addition, monodispersed leaf-like manganese–tungsten–oxide (Mn–W–Ox) nanoparticles and hydroxylated hexagonal boron nitride (h-BN) were synthesized and used as novel catalysts in OCM reaction. Preliminary results indicate that the MCF–17 supported Mn–W–Ox nanoparticle catalyst showed a CH4 conversion of 5.4% and C2 selectivity of 42% with good stability over time. On the other hand, hydroxylated h-BN exhibited good activity (~20% CH4 conversion) with moderate selectivity towards C2 hydrocarbons (20%–30%). However, the hydroxylated h-BN catalysts faced serious deactivation, which was not eliminated by lowering the reaction temperature or the oxygen concentration in the reaction gas feed.

Oxidative Coupling of Methane on Perovskite Type Oxides

Oxidative Coupling of Methane on Perovskite Type Oxides PDF Author: Wenzhong An
Publisher:
ISBN:
Category : Catalysis
Languages : en
Pages : 214

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Methane Conversion

Methane Conversion PDF Author: D.M. Bibby
Publisher: Elsevier
ISBN: 0080960707
Category : Technology & Engineering
Languages : en
Pages : 759

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Book Description
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.

Direct Natural Gas Conversion to Value-Added Chemicals

Direct Natural Gas Conversion to Value-Added Chemicals PDF Author: Jianli Hu
Publisher: CRC Press
ISBN: 0429663242
Category : Science
Languages : en
Pages : 368

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Book Description
Direct Natural Gas Conversion to Value-Added Chemicals comprehensively discusses all major aspects of natural gas conversion and introduces a broad spectrum of recent technological developments. Specifically, the book describes heterogeneous and homogeneous catalysis, microwave-assisted conversion, non-thermal plasma conversion, electrochemical conversion, and novel chemical looping conversion approaches. Provides an excellent benchmark resource for the industry and academics Appeals to experienced researchers as well as newcomers to the field, despite the variety of contributing authors and the complexity of the material covered Includes all aspects of direct natural gas conversion: fundamental chemistry, different routes of conversion, catalysts, catalyst deactivation, reaction engineering, novel conversion concepts, thermodynamics, heat and mass transfer issues, system design, and recent research and development Discusses new developments in natural gas conversion and future challenges and opportunities This book is as an excellent resource for advanced students, technology developers, and researchers in chemical engineering, industrial chemistry, and others interested in the conversion of natural gas.

Methane Oxidation Over Dual Redox Catalysts

Methane Oxidation Over Dual Redox Catalysts PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 135

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Book Description
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.

Methane Combustion over Lanthanum-based Perovskite Mixed Oxides

Methane Combustion over Lanthanum-based Perovskite Mixed Oxides PDF Author: Hamidreza Arandiyan
Publisher: Springer
ISBN: 366246991X
Category : Science
Languages : en
Pages : 123

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Book Description
This book presents current research into the catalytic combustion of methane using perovskite-type oxides (ABO3). Catalytic combustion has been developed as a method of promoting efficient combustion with minimum pollutant formation as compared to conventional catalytic combustion. Recent theoretical and experimental studies have recommended that noble metals supported on (ABO3) with well-ordered porous networks show promising redox properties. Three-dimensionally ordered macroporous (3DOM) materials with interpenetrated and regular mesoporous systems have recently triggered enormous research activity due to their high surface areas, large pore volumes, uniform pore sizes, low cost, environmental benignity, and good chemical stability. These are all highly relevant in terms of the utilization of natural gas in light of recent catalytic innovations and technological advances. The book is of interest to all researchers active in utilization of natural gas with novel catalysts. The research covered comes from the most important industries and research centers in the field. The book serves not only as a text for researcher into catalytic combustion of methane, 3DOM perovskite mixed oxide, but also explores the field of green technologies by experts in academia and industry. This book will appeal to those interested in research on the environmental impact of combustion, materials and catalysis.