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Book The Investigation of Nickel based Catalysts for the Oxidative Dehydrogenation of Ethane

Download or read book The Investigation of Nickel based Catalysts for the Oxidative Dehydrogenation of Ethane written by Justin Lane Park and published by . This book was released on 2019 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: The improved rates of ethylene formation observed with these catalysts led to the initial development of a commercially viable nickel based catalyst. The support interactions of NiO with a novel silica doped alumina support show higher yields than previously reported studies of NiO on alumina for ODH. These initial metal support interactions show that the addition of the niobium and ceria to this catalyst should give ethylene yields that are satisfactory for the commercialization of this catalyst.

Book The Oxidative Dehydrogenation of Ethane

Download or read book The Oxidative Dehydrogenation of Ethane written by Edrick Morales and published by . This book was released on 1988 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Catalytic Oxidative Dehydrogenation of Ethane

Download or read book Catalytic Oxidative Dehydrogenation of Ethane written by Shannon L. Lashbrook and published by . This book was released on 2001 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Oxidative Dehydrogenation of Ethane Over Supported Alkali Chloride Catalysts

Download or read book Oxidative Dehydrogenation of Ethane Over Supported Alkali Chloride Catalysts written by Christian Achim Gärtner and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Discovery and Development of Heterogeneous Catalysts for the Oxidative Dehydrogenation of Alkanes

Download or read book Discovery and Development of Heterogeneous Catalysts for the Oxidative Dehydrogenation of Alkanes written by Joseph Grant and published by . This book was released on 2018 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent surge in shale gas resources creates new opportunities to improve process efficiencies for the production of important chemical building blocks. Non-oxidative dehydrogenation of propane (PDH), the primary "on-purpose" propylene technology used worldwide today, has process inefficiencies that may be improved by co-feeding oxygen and propane to drive the oxidative dehydrogenation (ODH) of propane reaction. However, after decades of catalyst research for ODH of propane this reaction has yet to be commercialized due to the difficulty of controlling this partial oxidation to selectively yield propylene rather than the more-thermodynamically stable CO and CO2 (COx) products. This thesis explores the reactivity and properties of two very different classes of catalysts for the ODH of alkanes: 1) supported vanadia and 2) boron-containing catalysts. Supported vanadia catalysts, the most-studied catalyst for this transformation in the literature, show markedly higher selectivity to propylene when existing as dispersed two-dimensional metal oxide surface species. By introducing a small amount of Na+ to the surface of SiO2, the maximum two-dimensional surface density can be dramatically enhanced. This effect is proved using spectroscopic characterization, as well as the ODH of propane used as a probe reaction. Boron-containing compounds, especially boron nitride (BN) materials, were previously overlooked as catalysts for the ODH of alkanes, and rather deemed to be inert. On the contrary, these B-containing catalysts are now considered to be among the most-selective catalysts for the ODH of alkanes as a method to form their corresponding olefins. The rate of alkane consumption is dependent on oxygen adsorption to the catalyst surface, and shows second-order dependence in the concentration of the alkane. At these temperatures (400-500°C) oxygen adsorption to the B-containing catalyst only occurs when exposed to the ODH reaction (not only air or a combination of air and steam), and is verified with numerous spectroscopic techniques including X-ray Photoelectron Spectroscopy (XPS), and Attenuated Total Reflectance Infrared (ATR-IR). Recent work with X-ray Absorption Spectroscopy (XAS) and 11B MAS NMR dismisses the possibility that a potential B2O3 surface layer acts as the active site by revealing that B2O3 is not present on spent catalysts.

Book The Oxidative Dehydrogenation of Ethane Using Promoted Lithium Doped Magnesium Oxide Catalysts

Download or read book The Oxidative Dehydrogenation of Ethane Using Promoted Lithium Doped Magnesium Oxide Catalysts written by Hendrik Maarten Swaan and published by . This book was released on 1992 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Development and Characterization of Oxyfunctionalized Boron Nitride Catalysts for the Oxidative Dehydrogenation of Light Alkanes to Olefins

Download or read book Development and Characterization of Oxyfunctionalized Boron Nitride Catalysts for the Oxidative Dehydrogenation of Light Alkanes to Olefins written by Theodore Agbi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light olefins like ethylene and propylene are platform chemicals integral to the chemical industry. Production of polymers, oxygenates, and other important chemical intermediates demand global production volumes that top 100 million metric tons per year. Production of these light olefins, traditionally through steam cracking, is one of the most energy intensive processes in petrochemical sector. Changing refinery feedstocks (i.e. increased availability of natural gas) have created both necessity and opportunity for 'On-Purpose' propylene technologies to meet propylene demands. The oxidative dehydrogenation of propane to propylene (ODHP) is an attractive alternative process to produce propylene. ODHP enables lower process temperatures and avoids coke deactivation of the catalyst, and has the potential to significantly ease energy, capital, and material intensities of industrial propylene production. To-date, metal oxide ODHP catalysts like vanadia-based catalysts-the previous state of the art ODHP catalyst-do not achieve competitive propylene yields to make them industrially viable. The pioneering work of our research group has identified BN-a material renowned for its chemical inertness-as a highly reactive, selective, and stable ODHP catalyst. Since this discovery, we have worked to understand the fundamental reaction mechanisms present and identify structure-performance relationships that may further develop this class of catalyst. To-date, we have developed extensive spectroscopic characterization capabilities to identify the oxyfunctionalized boron layer formed in situ which contains highly dynamic active species responsible for the high reactivity and selectivity observed. Understanding the activation of molecular O2 and functionality of the oxyfunctionalized layer has been a highly collaborative process requiring a myriad of complimentary spectroscopic and reaction studies to develop fundamental insights. As such, I will provide a comprehensive context of our evolving knowledge in this collaborative project that have since been published where possible and will focus mainly on the recent insights made in this work. The work presented in this dissertation characterizes and probes the reactivity of the highly dynamic oxyfunctionalized surface layer that has been correlated with the reactivity and selectivity observed on this catalyst. Herein, the coordination environment of B and extent of oxyfunctionalization were analyzed via X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), and Attenuated Total Reflectance IR (ATR-IR) as a function of the reaction progress. Corresponding reaction studies show direct correlation between the development of tri-coordinated oxygenated B networks and the increasing reactivity and selectivity of the reaction during the catalyst's activation period. The significance of a set of reaction parameters was then examined to identify process levers conducive to oxyfunctionalization quantified by XPS. The acid-base activity of these surface tri-coordnated B networks in the oxyfunctionalized layer are examined via two prototypical reactions: (1) isopropanol decomposition and (2) formic acid decomposition. Catalytic reaction via flow through reactor and temperature programmed decomposition (TPD) studies using Diffuse Reflectance Infrared Fourier Transform IR spectroscopy (DRIFTs) and Mass Spectrometry (MS) are used to extract insights for the adsorption modes of alkoxides and formates their decomposition pathways. Observed surface reactions of isopropoxy intermediates under these conditions are used to understand possible surface reaction pathways available under ODHP conditions. The role of O2 in specific homogeneous pathways of the mixed hetero-homogeneous mechanism previously proposed by us and for supported boron oxide materials are examined. A simplified model for the surface-initiated radical oxidation chemistry pathways, was then used to probe a selectivity descriptor based on the different reactivities of propyl radicals. Using this knowledge, we design, and test model 3D printed BN based monoliths that optimize homogeneous reaction pathways. These catalysts are shown to be highly active and selective and stable for ~2.5wks. The results also suggest that oxygenates may be relevant products from homogeneous reactions. "The Boron Project," as we so lovingly called it, has seen several PhD students matriculate as we contributed diligently to uncovering the behavior of this material. The goal of this work is to highlight new avenues through which we can further understand surface reactivity, new tools through which we can probe gas phase radical chemistries, and new catalyst design approaches.

Book Direct Natural Gas Conversion to Value Added Chemicals

Download or read book Direct Natural Gas Conversion to Value Added Chemicals written by Jianli Hu and published by CRC Press. This book was released on 2020-09-25 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Book Reforming and Oxidative Dehydrogenation of Ethane with CO2 as a Soft Oxidant Over Bimetallic Catalysts

Download or read book Reforming and Oxidative Dehydrogenation of Ethane with CO2 as a Soft Oxidant Over Bimetallic Catalysts written by and published by . This book was released on 2016 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: An efficient mitigation of abundantly available CO2 is critical for sustainable environmental impact as well as for novel industrial applications. Using ethane, CO2 can be catalytically converted into a useful feedstock (synthesis gas) and a value-added monomer (ethylene) via the dry reforming pathway through the C-C bond scission and the oxidative dehydrogenation pathway through the C-H bond scission, respectively. Results from the current flow-reactor study show that the precious metal bimetallic CoPt/CeO2 catalyst undergoes the reforming reaction to produce syngas with enhanced activity and stability compared to the parent monometallic catalysts. In this paper, in order to replace Pt, the activities of non-precious CoMo/CeO2 and NiMo/CeO2 are investigated and the results indicate that NiMo/CeO2 is nearly as active as CoPt/CeO2 for the reforming pathway. Furthermore, FeNi/CeO2 is identified as a promising catalyst for the oxidative dehydrogenation to produce ethylene. Finally, density functional theory (DFT) calculations are performed to further understand the different pathways of the CoPt/CeO2 and FeNi/CeO2 catalysts.

Book Coke Formation on Metal Surfaces

Download or read book Coke Formation on Metal Surfaces written by Lyle Frederick Albright and published by . This book was released on 1982 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Mechanistic Insights on the Oxidative Dehydrogenation of Light Alkanes Catalyzed by Boron based Catalysts

Download or read book Mechanistic Insights on the Oxidative Dehydrogenation of Light Alkanes Catalyzed by Boron based Catalysts written by Juan Mauricio Venegas and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light olefins such as ethylene and propylene form the foundation of the modern chemical industry, with yearly production volumes well into the hundreds of millions of metric tons. Currently, these light olefins are mainly produced via energy-intensive steam cracking. Alternatively, oxidative dehydrogenation (ODH) of light alkanes to produce olefins allows for lower operation temperatures and extended catalyst lifetimes, providing valuable process efficiencies. This route has led to significant research interest due to the wide availability of natural gas from shale deposits. Advances in this area have still not yielded catalysts that are sufficiently selective to olefins for industrial implementation, and ODH still remains a holy grail of selective alkane oxidation research. Research into selective heterogeneous catalysts for the ODH of propane has led to the extensive use of vanadium oxide-based catalysts, and studies on the surface mechanism involved have been used to improve the catalytic activity of the material. Despite decades of research, however, selectivity towards propylene has not proven satisfactory at industrially-relevant conversions. In this thesis, I will present the serendipitous discovery and subsequent development of hexagonal boron nitride (hBN) and other boron-containing catalysts as selective ODH catalysts. Specifically, I will illustrate the evolution of our understanding of the chemical origin of the reactivity of these materials, which until our initial discovery were deemed chemically inert. By combining reactivity studies with spectroscopic characterization highlighted a unique interaction between boron and oxiygen that differs from that of metal oxides. This methodical characterization of catalytic activity and structural changes of hBN during ODH prompted us to zero in on oxidized boron species, not hBN itself, as the true catalyst of alkane oxidation. In turn, this discovery led us to describe a whole class of B-containing materials that share (and often improve upon) the catalytic performance of hBN. At this point, we decided to step away from material studies and instead improve our understanding on how the catalytic performance of hBN is affected by reactor operating parameters. In particular, we investigated the role of heat and mass transfer on catalytic performance. Unexpectedly, we were once again surprised by hBN when various experimental results during these efforts suggested the significance of gas phase chemistry on ODH performance. For example, we observed that upon dilution of hBN with an inert thermal conductor (to mitigate hotspot formation), the observed reactivity scales with total bed volume rather than hBN mass. Up until these studies, we expected all reactivity to stem from oxidized boron species, but these may be only a part of a more complex surface-gas phase reaction network. The final portion of this thesis presents our latest efforts to understand the role of each reactant on surface and gas phase reaction pathways. Within this work, we incorporate water into our reaction feeds to assess its influence as a source of gas phase radical species to carry out propane activation. Indeed, we observe significant rate enhancements by addition of water. This reactivity enhancement likely involves influencing reactive species concentrations primarily in the gas phase and, to a lesser extent, altering the surface composition during ODH. Overall, this thesis expands our understanding of B-based materials as ODH catalysts and highlights the importance of considering gas phase radical chemistry in future process development.