Deactivation and Regeneration of Zeolite Catalysts

Deactivation and Regeneration of Zeolite Catalysts PDF Author: M. Guisnet
Publisher: World Scientific
ISBN: 1848166370
Category : Science
Languages : en
Pages : 359

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Book Description
In chemical processes, the progressive deactivation of solid catalysts is a major economic concern and mastering their stability has become as essential as controlling their activity and selectivity. For these reasons, there is a strong motivation to understand the mechanisms leading to any loss in activity and/or selectivity and to find out the efficient preventive measures and regenerative solutions that open the way towards cheaper and cleaner processes. This book covers in a comprehensive way both the fundamental and applied aspects of solid catalyst deactivation and encompasses the state-of-the-art in the field of reactions catalyzed by zeolites. This particular choice is justified by the widespread use of molecular sieves in refining, petrochemicals and organic chemicals synthesis processes, by the large variety in the nature of their active sites (acid, base, acid-base, redox, bifunctional) and especially by their peculiar features, in terms of crystallinity, structural order and textural properties, which make them ideal models for heterogeneous catalysis. The aim of this book is to be a critical review in the field of zeolite deactivation and regeneration, by collecting a series of contributions by experts in the field which describe the factors, explain the techniques to study the causes and suggest methods to prevent (or limit) catalyst deactivation. At the same time, an anthology of commercial processes and exemplar cases provides the reader with theoretical insights and practical hints on the deactivation mechanisms and draws attention to the key role played by the loss of activity on process design and industrial practice.

Deactivation and Regeneration of Zeolite Catalysts

Deactivation and Regeneration of Zeolite Catalysts PDF Author: M. Guisnet
Publisher: World Scientific
ISBN: 1848166370
Category : Science
Languages : en
Pages : 359

Get Book Here

Book Description
In chemical processes, the progressive deactivation of solid catalysts is a major economic concern and mastering their stability has become as essential as controlling their activity and selectivity. For these reasons, there is a strong motivation to understand the mechanisms leading to any loss in activity and/or selectivity and to find out the efficient preventive measures and regenerative solutions that open the way towards cheaper and cleaner processes. This book covers in a comprehensive way both the fundamental and applied aspects of solid catalyst deactivation and encompasses the state-of-the-art in the field of reactions catalyzed by zeolites. This particular choice is justified by the widespread use of molecular sieves in refining, petrochemicals and organic chemicals synthesis processes, by the large variety in the nature of their active sites (acid, base, acid-base, redox, bifunctional) and especially by their peculiar features, in terms of crystallinity, structural order and textural properties, which make them ideal models for heterogeneous catalysis. The aim of this book is to be a critical review in the field of zeolite deactivation and regeneration, by collecting a series of contributions by experts in the field which describe the factors, explain the techniques to study the causes and suggest methods to prevent (or limit) catalyst deactivation. At the same time, an anthology of commercial processes and exemplar cases provides the reader with theoretical insights and practical hints on the deactivation mechanisms and draws attention to the key role played by the loss of activity on process design and industrial practice.

Zeolite Microporous Solids: Synthesis, Structure, and Reactivity

Zeolite Microporous Solids: Synthesis, Structure, and Reactivity PDF Author: E.G. Derouane
Publisher: Springer Science & Business Media
ISBN: 9401126046
Category : Science
Languages : en
Pages : 635

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Book Description
Intensive research on zeolites, during the past thirty years, has resulted in a deep understanding of their chemistry and in a true zeolite science, including synthesis, structure, chemical and physical properties, and catalysis. These studies are the basis for the development and growth of several industrial processes applying zeolites for selective sorption, separation, and catalysis. In 1983, a NATO Advanced Study Institute was organized in Alcabideche (portugal) to establish the State-of-the-Art in Zeolite Science and Technology and to contribute to a better understanding of the structural properties of zeolites, the configurational constraints they may exert, and their effects in adsorption, diffusion, and catalysis. Since then, zeolite science has witnessed an almost exponential growth in published papers and patents, dealing with both fundamentals issues and original applications. The proposal of new procedures for zeolite synthesis, the development of novel and sophisticated physical techniques for zeolite characterization, the discovery of new zeolitic and related microporous materials, progresses in quantum chemistry and molecular modeling of zeolites, and the application of zeolites as catalysts for organic reactions have prompted increasing interest among the scientific community. An important and harmonious interaction between various domains of Physics, Chemistry, and Engineering resulted therefrom.

Innovation in Zeolite Materials Science

Innovation in Zeolite Materials Science PDF Author: P.J. Grobet
Publisher: Elsevier
ISBN: 0080960715
Category : Technology & Engineering
Languages : en
Pages : 557

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Book Description
The proceedings of this zeolite scientific meeting reflect the growing drive to discover new materials. It is evident that zeolite materials science is in a post-ZSM-5 period - pushed by a massive expansion of new compositions and topologies, and the application of new scientific tools. Four new zeolite topologies were detailed at this meeting. Important new trends were the resurgence of interest in computational and theoretical approaches to explain synthesis, sorption and catalytic data, and the increasing use of NMR and high-resolution imaging.

Zeolites in Catalysis

Zeolites in Catalysis PDF Author: Jiří Čejka
Publisher: Royal Society of Chemistry
ISBN: 1782627847
Category : Science
Languages : en
Pages : 547

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Book Description
Accessible references for researchers and industrialists in this exciting field, covering both developments and applications of catalysis.

Mesoporous Zeolites

Mesoporous Zeolites PDF Author: Javier García-Martínez
Publisher: John Wiley & Sons
ISBN: 3527335749
Category : Technology & Engineering
Languages : en
Pages : 608

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Book Description
Authored by a top-level team of both academic and industrial researchers in the field, this is an up-to-date review of mesoporous zeolites. The leading experts cover novel preparation methods that allow for a purpose-oriented fine-tuning of zeolite properties, as well as the related materials, discussing the specific characterization methods and the applications in close relation to each individual preparation approach. The result is a self-contained treatment of the different classes of mesoporous zeolites. With its academic insights and practical relevance this is a comprehensive handbook for researchers in the field and related areas, as well as for developers from the chemical industry.

Zeolites For Cleaner Technologies

Zeolites For Cleaner Technologies PDF Author: Jean-pierre Gilson
Publisher: World Scientific
ISBN: 178326117X
Category : Science
Languages : en
Pages : 390

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Book Description
This book, written and edited by leading authorities from academia and industrial groups, covers both preventive- and curative-zeolite-based technologies in the field of chemical processing.The opening chapter presents the state of the art in zeolite science. The two subsequent chapters summarize the chemistries involved in the processes and the constraints imposed on the catalyst/adsorbent. Three major areas are covered: oil refining, petrochemicals and fine chemicals. A chapter on the (curative) use of zeolites in pollution abatement completes this overview.In the area of oil refining, a general lecture sets the scene for present and future challenges. It is followed by in-depth case studies involving FCC, hydrocracking and light naphtha isomerization. Also, an entire chapter is devoted to the often-overlooked subject of base oils.In the area of petrochemicals, the processing of aromatics and olefins is described and special attention is paid to the synergy between catalysis and separation on molecular sieves.

Feedstock Recycling of Plastic Wastes

Feedstock Recycling of Plastic Wastes PDF Author: Jose Aguado
Publisher: Royal Society of Chemistry
ISBN: 1847550800
Category : Technology & Engineering
Languages : en
Pages : 205

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Book Description
The use of plastic materials has seen a massive increase in recent years, and generation of plastic wastes has grown proportionately. Recycling of these wastes to reduce landfill disposal is problematic due to the wide variation in properties and chemical composition among the different types of plastics. Feedstock recycling is one of the alternatives available for consideration, and Feedstock Recycling of Plastic Wastes looks at the conversion of plastic wastes into valuable chemicals useful as fuels or raw materials. Looking at both scientific and technical aspects of the recycling developments, this book describes the alternatives available. Areas include chemical depolymerization, thermal processes, oxidation and hydrogenation. Besides conventional treatments, new technological approaches for the degradation of plastics, such as conversion under supercritical conditions and coprocessing with coal are discussed. This book is essential reading for those involved in plastic recycling, whether from an academic or industrial perspective. Consultants and government agencies will also find it immensely useful.

Chemical Catalysts for Biomass Upgrading

Chemical Catalysts for Biomass Upgrading PDF Author: Mark Crocker
Publisher: John Wiley & Sons
ISBN: 3527344667
Category : Technology & Engineering
Languages : en
Pages : 634

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Book Description
A comprehensive reference to the use of innovative catalysts and processes to turn biomass into value-added chemicals Chemical Catalysts for Biomass Upgrading offers detailed descriptions of catalysts and catalytic processes employed in the synthesis of chemicals and fuels from the most abundant and important biomass types. The contributors?noted experts on the topic?focus on the application of catalysts to the pyrolysis of whole biomass and to the upgrading of bio-oils. The authors discuss catalytic approaches to the processing of biomass-derived oxygenates, as exemplified by sugars, via reactions such as reforming, hydrogenation, oxidation, and condensation reactions. Additionally, the book provides an overview of catalysts for lignin valorization via oxidative and reductive methods and considers the conversion of fats and oils to fuels and terminal olefins by means of esterification/transesterification, hydrodeoxygenation, and decarboxylation/decarbonylation processes. The authors also provide an overview of conversion processes based on terpenes and chitin, two emerging feedstocks with a rich chemistry, and summarize some of the emerging trends in the field. This important book: -Provides a comprehensive review of innovative catalysts, catalytic processes, and catalyst design -Offers a guide to one of the most promising ways to find useful alternatives for fossil fuel resources -Includes information on the most abundant and important types of biomass feedstocks -Examines fields such as catalytic cracking, pyrolysis, depolymerization, and many more Written for catalytic chemists, process engineers, environmental chemists, bioengineers, organic chemists, and polymer chemists, Chemical Catalysts for Biomass Upgrading presents deep insights on the most important aspects of biomass upgrading and their various types.

Regeneration of Spent Catalyst and Impregnation of Catalyst by Supercritical Fluid

Regeneration of Spent Catalyst and Impregnation of Catalyst by Supercritical Fluid PDF Author: Farid Gumerov
Publisher: Nova Science Publishers
ISBN: 9781634843096
Category : Catalysts
Languages : en
Pages : 0

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Book Description
A catalyst is a material of constant composition, which accelerates the rate of a chemical reaction by providing a suitable reaction pathway with the lowest activation energy. As the activation energy is lower, more reaction products are formed in the same period of time. Most catalytic reactions encountered in hydrocarbon processing are carried out with porous catalysts to provide a sufficient surface area for the metal dispersion and the ensuing reaction. These catalysts gradually lose their catalytic activity, usually through structural changes, poisoning, or the deposit of extraneous material. A catalyst which can no longer exhibit the necessary activity and/or is specificity required by the user is referred to as a "spent catalyst". Catalysts are critical to the chemical industry and are now used in most industrial chemical processes. Along with the rapid development and wide application of catalysis technology, the amounts of different spent catalysts are increased from year to year. The physical properties of spent catalysts, as well as their composition, are generally different from those of fresh catalysts. For example, spent hydrotreating catalysts contain metal sulfides and coke, and may have additional contaminants that were not present in the fresh catalyst. Catalyst regeneration involves the processing of spent catalysts in order to make them reusable. This is done by restoring the initial properties of spent catalysts and thus restoring their efficiency through a process called regeneration of catalysts. Traditional methods of vapor-air regeneration are energy-consuming and severely limit the number of regeneration cycles. Using supercritical fluid CO2-extraction process, according to some estimates, provides a two-fold energy savings and an increasing number of regeneration cycles possible. This book gathers a series of studies describing new methods for the regeneration of heterogeneous catalysts for important industrial chemical processes. In this book we propose new extraction techniques using supercritical fluid extraction (SFC), which seems to be one of the most promising as a green reaction medium. The feasibility of using supercritical fluid СО2 extraction process was investigated in particular for spent catalyst regeneration. The low regeneration temperature of supercritical carbon dioxide eliminates the risk of thermal deterioration of the catalyst (namely the collapse of the pores), prevents the reduction of the surface area and the sintering, and allows regeneration of catalysts with an activity close to that of fresh catalysts. The results of the implementation of the supercritical fluid СО2 extraction process with respect to samples of industrial deactivated catalysts are provided. A comparison of the characteristics of the regenerated catalyst samples by traditional approaches and the SC-CO2 extraction process is carried out. The possibility of using a supercritical fluid CO2 impregnation technique in the synthesis of a palladium catalyst is also studied.

Fast Pyrolysis of Biomass

Fast Pyrolysis of Biomass PDF Author: Robert C Brown
Publisher: Royal Society of Chemistry
ISBN: 1782626182
Category : Science
Languages : en
Pages : 291

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Book Description
Fast pyrolysis and related catalytic pyrolysis are of increasing interest as pathways to advanced biofuels that closely mimic traditional petroleum products. Research has moved from empirical investigations to more fundamental studies of pyrolysis mechanisms. Theories on the chemical and physical pathways from plant polymers to pyrolysis products have proliferated as a result. This book brings together the latest developments in pyrolysis science and technology. It examines, reviews and challenges the unresolved and sometimes controversial questions about pyrolysis, helping advance the understanding of this important technology and stimulating discussion on the various competing theories of thermal deconstruction of plant polymers. Beginning with an introduction to the biomass-to-biofuels process via fast pyrolysis and catalytic pyrolysis, chapters address prominent questions such as whether free radicals or concerted reactions dominate deconstruction reactions. Finally, the book concludes with an economic analysis of fast pyrolysis versus catalytic pyrolysis. This book will be of interest to advanced students and researchers interested in the science behind renewable fuel technology, and particularly the thermochemical processing of biomass.