Ulteriori informazioni
Hydrotreating processes in petroleum refining were introduced more than 50 years ago for the removal of sulfur and nitrogen. The sulfided cobalt-molybdenum catalyst, together with its near relatives, is still widely used. Two oil crises made it clear that pretroleum reserves are not inexhaustible and we shall be compelled to exploid less satisfactory sources with high sulfur and nitrogen making hydrotreating even more important. This review is particularly timely for the reason that only recently has a detailed understanding of process chemistry and catalyst structure been obtained. The authors concentrate on the catalytic chemistry of the processes, dealing in some detail with the structure of the most important types of catalysts and the relationship of structure to activity.
Sommario
Hydrotreating Catalysis.- 1. Introduction.- 2. Technological Aspects.- A. Crude and Feed Characteristics.- B. Hydrotreating Reactions.- C. Hydrotreating in Refining.- D. Hydrotreating Processes.- E. Catalyst Selection.- F. Activation,Deactivation and Regeneration.- 3. Catalyst Characterization.- A. Structural Models.- 1. Monolayer Model.- 2. Intercalation Model.- 3. Contact Synergy Model.- 4. Co-Mo-S Model.- 5. Other Models.- B. Characterization Studies.- 1. Structure of Alumina-supported Mo and W Catalysts.- a. Unpromoted Catalysts.- i. Calcined Catalysts.- ii. Sulfided State.- b. Promoted Catalysts.- i. Calcined State.- ii. Sulfided State.- 2. Other Supports.- 3. Sulfiding Reactions.- 4. Effect of Preparation and Activation.- a. Impregnation Procedure.- b. Metal Loading.- c. Calcination Temperature.- d. Activation.- e. Additives.- 5. Dispersion and Morphology.- 6. Aged Catalysts.- 7. Unsupported Catalysts.- 8. New Types of Hydrotreating Catalysts.- 9. Model Systems.- 4. Kinetics and Mechanisms of Model Compound Reactions.- A. Hydrodesulfurization (HDS).- 1. Reactivities.- 2. Reaction Pathways.- 3. Kinetics.- 4. Poisoning/Coke.- 5. Adsorption/Reaction Sites.- 6. Mechanisms.- 7. Implications from Organometallic and Computational Chemistry.- B. Hydrogenation (HYD).- 1. Reactivities.- 2. Reaction Pathways and Kinetics.- 3. Adsorption/Reaction Sites.- C. Hydrodenitrogenation (HDN).- 1. Reactivities.- 2. Reaction Pathways and Kinetics.- 3. Promotion/Poisoning/Coke.- 4. Adsorption/Reaction Sites.- 5. Mechanisms.- D. Hydrodeoxygenation (HDO).- 1. Reactivities.- 2. Reaction Pathways and Kinetics.- 3. Poisons/Coke.- 4. Adsorption/Reaction Sites.- E. Cracking (CKG)/Hydrocracking.- F. Hydrodemetallation (HDM).- G. Mixed Feeds.- 1. Reactivities.- 2. Kinetics.- H. Role of Hydrogen.- I. On Active Sites.- J. Summary.- 5. Structure-Activity Correlations.- A. Unpromoted Mo and W Catalysts.- B. Promoted Mo and W Catalysts.- 1. Models for Promotion.- 2. Mössbauer Spectroscopy Studies.- 3. Chemisorption of Probe Molecules and Infrared Spectroscopy Studies.- a. 0 2.- b. NO.- c. CO.- d. H2, H2S and basic molecules.- 4. EXAFS Studies.- 5. XPS, ISS and Microscopy Studies.- 6. Magnetic Susceptibility, NMR, and ESR Studies.- 7. TPR.- 8. Other Studies.- C. Correlations with Properties of Calcined Catalysts.- D. Preparation Parameters.- 1. MetalLoading.- 2. Impregnation procedure.- 3. Calcination temperature.- E. Additive Effects.- F. Periodic Trends in Promotion.- G. Activation Procedures.- H. Deactivation Phenomena.- I. Unsupported Catalysts and Support Effects.- J. Transition Metal Sulfides: Periodic Trends.- K. Unconventional Catalysts and Model Systems.- 6. Active Sites and Reaction Mechanisms.- A. Unpromoted Mo and W Catalysts.- B. Periodic Trends.- C. Promoted Mo and W Catalysts.- 7. Concluding Remarks.- 8. References.- References Author Index.- Author Index Volumes 1 11.
