Deactivation and Regeneration of Zeolite Catalysts Catalytic Science Imperial College Press

"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 the fundamental and applied aspects of solid catalyst deactivation in a comprehensive way 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 contributions from 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, a selection 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."-- Publisher's website Preface Foreword Authors Acknowledgements Contents Part I: Introduction to Zeolites and to Deactivation Phenomena Chapter 1: Deactivation and Regeneration of Solid Catalysts 1.1. Introduction 1.2. Causes Of Deactivation 1.3. How To Prevent, Limit And Cure The Deactivation Of Solid Catalysts? 1.4. Good Engineering Practice 1.5. Conclusion References Chapter 2: Zeolites As Models For Understanding Catalyst Deactivation And Regeneration 2.1. Introduction 2.2. Pore Structure 2.3. Active Sites 2.4. Shape Selectivity 2.5. Conclusion References Part II: Characterization Methods Chapter 3: Methods to Simulate Catalyst Deactivation 3.1. Introduction 3.2. Types Of Deactivation 3.3. Deactivation Tests And Performance Predictions 3.3.1. 3.4. Characterization Of Industrial Catalysts 3.5. Conclusion References Chapter 4: Characterization of Deactivating Species 4.1. Introduction 4.2. Methods For Coke Characterization 4.3. Amount And Elemental Composition 4.3.1. 4.4. Chemical Nature Of Coke Components 4.5. Chemical Composition Of “coke” 4.5.1. 4.6. Conclusion References Chapter 5: Characterization of Aged Zeolite Catalysts 5.1. Introduction 5.2. Physisorption Of Probe Molecules 5.3. Chemisorption Of Probe Molecules 5.3.1. 5.4. Physical Methods 5.5. Conclusion References Part III: Deactivation Mechanisms Chapter 6: Poisoning of Zeolite Catalysts 6.1. Introduction 6.2. Deactivating Effects Of Poisons 6.2.1. 6.3. Poisoning Of Acid Zeolite Catalysts By Basic Compounds 6.4. Poisoning Of Noble Metal Zeolite Catalysts By Sulphur Compounds 6.5. Conclusion References Chapter 7: Modes of Coke Formation and Deactivation 7.1. Introduction 7.2. Coke Formation 7.3. Modes of Deactivation 7.4. Conclusion References Chapter 8: Thermal Alterations of Zeolite Catalysts 8.1. Introduction 8.2. Transformation Of Active Phases During The Catalytic Destruction Of Dichloromethane (dcm) 8.3. Structural Alteration Of Acid Zeolite Catalysts 8.4. Sintering Of Noble Metals Supported On Zeolites 8.4.1. 8.5. Conclusion References Chapter 9: Modelling of Deactivation by Coke Formation 9.1. Introduction 9.2. Modelling Of Zeolite Deactivation By Coke Formation 9.3. Case Study: Fluid Catalytic Cracking 9.4. Conclusion References Part IV: Prevention of Deactivation and Optimal Regeneration Chapter 10: Selection of Process and Mode of Operation 10.1. Introduction 10.2. Evolution Of Refining And Petrochemical Industries 10.3. Heterogeneous Catalytic Reactor Technologies 10.4. Selection Of Optimal Reactor Technology 10.5. Case Studies 10.6. Conclusion References Chapter 11: Prevention of Zeolite Deactivation by Coking 11.1. Introduction 11.2. Parameters Determining The Rate Of Coking 11.2.1. 11.3. Parameters Determining The Deactivating Effect Of Coke 11.4. Guidelines For Preventing Deactivation References Chapter 12: Regeneration of Coked Zeolite Catalysts 12.1. Introduction 12.2. Removal Of High-temperature Coke 12.2.1. 12.3. Removal Of Low-temperature Coke 12.4. Conclusion References Part V: Case Studies Chapter 13: Deactivation and Regeneration of FCC Catalysts 13.1. Introduction 13.2. Main Characteristics Of The Fcc Process 13.2.1. 13.3. Catalyst Deactivation And Regeneration 13.4. Deactivation Of Additives 13.5. Final Remarks References Chapter 14: Hydrocracking 14.1. Introduction 14.2. Main Characteristics Of The Hydrocracking Process 14.2.1. 14.3. Catalyst Deactivation 14.4. Regeneration And Recycling 14.5. Conclusion References Chapter 16: Aromatization Of C6, C7 Paraffins Over Pt/ltl Catalysts 16.1. Introduction 16.2. Aromatization Mechanisms And Active Sites 16.3. What Makes The Ltl Zeolite So Well-adapted To Aromatization? 16.4. Deactivation Of Pt-zeolite Reforming Catalysts 16.5. How To Prevent The Catalyst Deactivation? References Chapter 15: Methanol to Olefins: Coke Formation and Deactivation 15.1. Introduction 15.2. Methanol To Olefins 15.3. Coke Formation In The Mto Reaction 15.3.1. 15.4. Catalyst Deactivation During The Mto Reaction 15.4.1. 15.5. Effects Of Coke On Shape Selectivity 15.6. Conclusion References Chapter 17: Deactivation Of Molecular Sieves In The Synthesis Of Organic Chemicals 17.1. Introduction 17.2. Peculiar Factors Leading To Deactivation Of Molecular Sieves In Organic Synthesis 17.3. Exemplar Cases 17.4. Conclusion Acknowledgements References Index 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. This book covers in a comprehensive way both the fundamental and applied aspects of solid catalyst deactivation.