Author: Gurdeep Singh Ranhotra
Publisher:
ISBN:
Category :
Languages : en
Pages : 268

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Author: B. Delmon
Publisher: Elsevier
ISBN: 0080534260
Category : Technology & Engineering
Languages : en
Pages : 459

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Book Description
The 2nd International Symposium on Hydrotreatment and Hydrocracking of Oil Fractions, which is also the 7th in the series of European Workshops on Hydrotreatment, took place in Antwerpen, Belgium from November 14 to 17. The Symposium emphasized how oil refining faces increasingly severe environmental regulations. These and the increasing application of heavier crudes containing more S-, N- and metal components call for more efficient hydrotreatment and hydrocracking processes. It is clear from the keynote lectures, the oral contributions and the posters of this meeting that adapting the operating conditions will not suffice. Adequate catalysts need to be developed, with different composition and structure. Surface science techniques and molecular modeling are now well established tools for such a development. They should be of help in widely different aspects, like the role of precursors in the preparation or the modifications undergone by the catalyst under reaction conditions. The improvement of hydrotreatment and hydrocracking also needs accurate modeling of the chemical reactor. This requires more representative hydrodynamics and kinetic models whose validity extends to the very low S- and N-contents. These areas should be vigorously developed.

Author: Karthick Murugappan
Publisher:
ISBN:
Category :
Languages : en
Pages : 176

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Growing concerns due to rising CO2 emissions have made biomass an indispensable source of renewable fuels and chemicals. However, biomass inherently has high oxygen content, which translates to low energy density, thereby necessitating a deoxygenation step before being utilized as fuels. Recently, MoO3 and Mo2C have emerged as promising earth-abundant cheap catalysts that perform hydrodeoxygenation (HDO) at relatively low temperatures ( 673 K) and ambient H2 pressures wherein oxygen is selectively removed as water. However, there exists a significant knowledge gap in understanding the stability and the active phases responsible for HDO of these catalysts. Furthermore, their applicability for real biomass conversions has not been largely demonstrated. In this thesis, first, HDO of m-cresol, a biomass-derived model compound, is investigated over bulk and supported MoO 3 catalysts. Detailed reactivity and characterization studies reveal that Mo5+ species plays a critical role during HDO. Specifically, TiO2 and ZrO2 are identified as ideal supports as they feature superior HDO reactivity and stability over bulk MoO3 by stabilizing intermediate Mo oxidation states (i.e. Mo5+) while bulk MoO 3 over-reduces to inactive metallic Mo. Translating from model compound studies, supported MoO3 catalysts are demonstrated to be effective in converting biomass (pine) pyrolysis vapors to hydrocarbons (ca. 30 % yield). In comparison with MoO 3, Mo2C is significantly more stable and selective for HDO of 4-methylanisole to toluene under identical reaction conditions. Mo2C predominantly breaks the stronger phenolic C-0 bond while MoO 3 also breaks the weaker aliphatic C-0 bond, likely due to the presence of Bronsted acid sites. To gain insights into the surface active sites, operando near-ambient XPS is employed during HDO and this technique revealed that HDO seems to operate via distinct active sites over both these materials. Finally, Mo2C is shown to be effective in upgrading real lignin streams to a single product propylbenzene, a precursor for renewable polymer. Overall, this thesis demonstrates the applicability of MoO3 and Mo2C in real biomass conversions and provides insights on the working nature of these catalysts, which will enable the design of more effective HDO catalysts.

Author: Michael Kraft Neylon
Publisher:
ISBN: 9780599634268
Category :
Languages : en
Pages :

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Author: Ge, Hui
Publisher: IGI Global
ISBN: 1522522751
Category : Technology & Engineering
Languages : en
Pages : 174

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Book Description
Mo(W)-Based Catalysts have the capacity to drastically impact many different industries. Research on their most current applications is important for the success of many organizations and companies, specifically the chemical and petroleum industries. Innovative Applications of Mo(W)-Based Catalysts in the Petroleum and Chemical Industry: Emerging Research and Opportunities is an informative resource that overviews emerging methods and techniques that incorporate 2D layer Mo(W) dichalcogenides. Featuring extensive coverage on a range of subjects including 2D nanosheets, hybridization, dichacogenides, and oxide based catalysts, this is an ideal publication for academicians, students, engineers, and researchers seeking insight on the latest advancements in Mo(W)-Based catalyst applications.

Author: Justin S J Hargreaves
Publisher: Royal Society of Chemistry
ISBN: 1788014839
Category : Science
Languages : en
Pages : 204

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Book Description
Many important industrial chemical processes rely heavily on catalysis and so researchers are always on the lookout for alternative catalytic materials that may improve existing processes or lead to new ones. Families of alternative catalytic materials currently being investigated include the carbides, nitrides and phosphides as well as amorphous boron catalysts. The addition of carbon, nitrogen or phosphorous to transition metals and the creation of boron-transition metal alloys leads to catalytic materials that have interesting properties, with applications in a range of different reactions, including electrocatalysis. This book provides a comprehensive account of the preparation, characterisation and application of these catalytic materials. It is an important reference for researchers and industrialists working in heterogeneous catalysis and materials chemistry.

Author: David Charles Lamont
Publisher:
ISBN:
Category : Catalytic reforming
Languages : en
Pages :

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Author: Dushyant Shekhawat
Publisher: Elsevier
ISBN: 0444535640
Category : Technology & Engineering
Languages : en
Pages : 569

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Book Description
Fuel Cells: Technologies for Fuel Processing provides an overview of the most important aspects of fuel reforming to the generally interested reader, researcher, technologist, teacher, student, or engineer. The topics covered include all aspects of fuel reforming: fundamental chemistry, different modes of reforming, catalysts, catalyst deactivation, fuel desulfurization, reaction engineering, novel reforming concepts, thermodynamics, heat and mass transfer issues, system design, and recent research and development. While no attempt is made to describe the fuel cell itself, there is sufficient description of the fuel cell to show how it affects the fuel reformer. By focusing on the fundamentals, this book aims to be a source of information now and in the future. By avoiding time-sensitive information/analysis (e.g., economics) it serves as a single source of information for scientists and engineers in fuel processing technology. The material is presented in such a way that this book will serve as a reference for graduate level courses, fuel cell developers, and fuel cell researchers. - Chapters written by experts in each area - Extensive bibliography supporting each chapter - Detailed index - Up-to-date diagrams and full colour illustrations

Author: Louis Toth
Publisher: Elsevier
ISBN: 032315722X
Category : Technology & Engineering
Languages : en
Pages : 296

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Book Description
Refractory Materials, Volume 7: Transition Metal Carbides and Nitrides discusses the developments in transition metal carbide and nitride research. This volume is organized into nine chapters that emphasize the mechanical and superconducting properties of these compounds. The introductory chapters deal with the general properties, preparation techniques, characterization, crystal chemistry, phase relationships, and thermodynamics of transition metal carbides and nitrides. The following chapter highlights the mechanical properties of these compounds, such as elastic and plastic deformation, fracture, strengthening mechanisms, and hardness. The discussion then shifts to specific electrical and magnetic properties, including electrical resistivity, Hall coefficient, and magnetic susceptibility. A separate chapter is devoted to carbides and nitrides as superconductors. The concluding chapters explore certain theories that explain the mechanisms of band structure and bonding in carbides and nitrides. This volume is of great value to research workers in metallurgy, ceramics, physics, chemistry, and related fields, as well as to advanced students investigating problems concerning high temperature materials or interstitial compounds.

Author: Jae Sung Lee
Publisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 520

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