Author: Ronald Wafula MusamaliPublisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 420
Book Description
Non-oxidative Conversion of Methane Into Carbon and Petrochemicals Over Fe, W,& Mo Catalyst Systems Supported on Activated Carbon and HZSM-5
Author: Ronald Wafula MusamaliPublisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 420
Book Description
Non-oxidative Conversion of Methane Over Mo-HZSM5 Catalysts
Author: James Ross AndersonNon-oxidative Conversion of Methane Into Aromatic Hydrocarbons Over Molybdenum Modified H-ZSM-5 Zeolite Catalysts
Author: Themba Emmanuel TshabalalaPublisher:
ISBN:
Category : Aromatic compounds
Languages : en
Pages : 254
Book Description
Methane Conversion by Oxidative Processes
Author: WolfPublisher: Springer Science & Business Media
ISBN: 9401574499
Category : Technology & Engineering
Languages : en
Pages : 556
Book Description
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.
Non-oxidative Methane Activation Over Molybdenum and Tungsten Nitrides
Author: Mohsen ShahryariPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
"The abundance of natural gas (methane) has gained enormous attention towards its use as a feedstock replacement in petrochemical industries. Canada is one world's top chemical and plastic manufacturing industries. Ethylene and aromatics are used largely (52% and 30% respectively) as feedstocks in petrochemical industries. Due to volatile oil price and its depletion, it makes it essential for refiners to look for a reliable feed replacement for optimum revenue, making methane gas a good candidate.Direct non-oxidative conversion of methane to olefins and aromatics can be a potential alternative to the conventional intermediate synthesis-gas production route. This process does not produce greenhouse gas and could also be used for clean hydrogen gas production. However, activation of the C-H bonds in CH4 is extremely challenging and thermodynamically limited, requiring high temperatures (700-1000°C) and an efficient catalyst. Also, selectivity and coking of the catalyst are considered a major challenge. In this master's thesis, the metal catalysts chosen are Ga, Mo, and W. Each of these metals has shown to be active towards methane activation. Metal nitrides are an alternative to noble-metal catalysts; our group has recently reported catalytic activity of gallium nitride towards methane activation. In this study, the catalytic performance of Mo, W, and mixed-metal Mo/W nitrides was investigated. The effect of atomic ratios of Mo and W on the methane conversion, product selectivity, and coke formation was evaluated. The study on gallium nitride catalyst and its regeneration capability was studied as collaborative work.The metal and mixed-metal nitride catalysts were synthesized via impregnation of the corresponding precursors onto SBA-15 with a total target metal loading of 4 wt% and varying atomic ratios between Mo and W. Impregnated catalysts were dried and subsequently calcined at 750°C to form metal oxides. Prior to the methane activation experiments, the metal oxides were either reduced in H2 at the 700°C for 1 h or nitridated under NH3 gas at 700°C for 3 h to form the corresponding metal nitrides. Reduction, nitridation, and activity experiments were carried out in the same fixed bed reactor setup at the same temperature (700°C) and GHSV of 1160 h−1 at 1 barabs. The product gas mixture was analyzed via a calibrated mass spectrometer, while the amount of coke was determined via temperature-programmed oxidation in a thermogravimetric analyzer (TGA). The catalysts were characterized using N2 adsorption/desorption, chemisorption, DRIFTS, XRD, SEM-EDS, and XPS to understand the structure-activity relationship.The methane conversion to hydrocarbons along with the coke formation and product selectivity of the catalysts were evaluated. Mo, W, and MoW catalysts have higher activity than the corresponding nitrides with Mo and MoN achieving a CH4 conversion to hydrocarbon values of 0.85 % and 0.55%, respectively. W and WN catalysts are slightly less active with CH4 conversions of 0.55% and 0.14%, respectively. Despite the lower CH4 conversion, the metal nitrides have a much lower coke formation and a much higher selectivity towards ethylene as aromatic species are more prone for coke formation. The lowest coke deposition was 8 mgCoke gCat−1 on WN/SBA-15 for the nitride compared to 110 mgCoke gCat−1 for the metal catalysts. The C2H4 selectivity is greatly increased with the relative amount of W. Mo and MoN achieve C2H4 selectivity of 10% and almost zero, respectively, while W and WN achieve 25% and 42% C2H4 selectivity. The highest C2H4 selectivity of 65% was reached with the mixed-metal nitride catalyst containing Mo:W ratio of 5:1. Using TGA, it was shown that the gallium nitride (GaN) catalyst could be successfully regenerated with air while maintaining a stable ethylene yield. The DRIFTS experiments confirmed the DFT work that ethylene is formed first followed by benzene formation over gallium in non-oxidative CH4 conversion"--
Methane Activation and Utilization in the Petrochemical and Biofuel Industries
Author: Hua SongPublisher: Springer Nature
ISBN: 3030884244
Category : Technology & Engineering
Languages : en
Pages : 264
Book Description
This book discusses effective and alternative uses for natural gas (NG) and highlights the utilization of NG in the field of methane activation and chemical production. It details the techniques used during the reforming process of petrochemical and bio-derived fuels and it presents cutting-edge research that describes the utilization of NG that enables it to be more cost-effective and eliminate the expensive greenhouse gas emitting process of hydrogen production. The book addresses three major topics: NG use in upstream heavy oil and bitumen upgrading, NG and its use in downstream oil refining through co-aromatization of various feeds in the petrochemical industry, and NG use in the upgrading of bio-derived fuels and discusses alternative uses of NG. In-depth chapters demonstrate uses for NG beyond heating homes, through catalysis and in-situ hydrogen donation, and its potential applications for the petrochemical and biofuel industries.
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-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
Methane Conversion by Oxidative Processes
Author: Eduardo E. WolfPublisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 566
Book Description
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.
Hydrogen and Syngas Production and Purification Technologies
Author: Ke LiuPublisher: John Wiley & Sons
ISBN: 0470561246
Category : Technology & Engineering
Languages : en
Pages : 564
Book Description
Covers the timely topic of fuel cells and hydrogen-based energy from its fundamentals to practical applications Serves as a resource for practicing researchers and as a text in graduate-level programs Tackles crucial aspects in light of the new directions in the energy industry, in particular how to integrate fuel processing into contemporary systems like nuclear and gas power plants Includes homework-style problems